I actually think it was Vivi that made Luffy more into a pirate like Shanks. Vivi kept Luffy's anger in check and kept him humble. Without vivi, Luffy would be closer to black beard sometimes
What if Garp knew that Shanks was a part of Roger's crew and he knew that Shanks would never harm anyone unprovoked, much like how no one goes after Rayleigh.
On top of that, Garp probably knows that Shanks gave up an arm for his grandson. So, while he probably dislikes Shanks for influencing Luffy, the way he did Garp has undeniable respectful Shanks at the same time.
@@TVmantitan779well ofc garps knows that. Luffy kept talking about it again and again when he was young. On top of that garp can’t go after shanks alone or well , we saw what happens when you go after a Yonko alone…
@@Gaurav_kattagyangarp is stronger than shanks back then. There's high probability that garp knows his fruit back then, and the reason why the awakening of his fruit will be the only way to reach one piece. They're both risking it all for the comeback of joy boy.
@@himgoat_999 Shanks still had a full crew of high level people, they called the most well rounded yonko crew for a reason, even if they were weaker than now a days, they didn´t exactly threaten Luffy like Koby is threatened by being a prisoner and yeah Shanks sacrificed his arm for Luffy, how people come even to compare those circumstances is a misterry to me.
What Garp did for Koby is probably supposed to be connected to what shanks did for Luffy as well, with them both being passing the torch to the next generation and all that
I think the easiest way of answering this is Blackbeard is clearly a Villain's Villain but Garp is a fan favourite hero fighting another fan favourite 😂 Oda probably got tempted but though nah I won't go there... they can dream of the outcome instead 💀
@@arthurramirez5665which one piece are you watching bro? Marines are literally the most corrupt organization, and they are literally controlled by some unknown celestial dragons who do injustice to the society,and those celestial dragons are controlled by 5 elders,who are also corrupt to an extent and moreover they were the one's who created the void century
@@Bl8zeyTechnically he's correct but legal doesn't equate to moral. The Straw Hats are protagonists and Luffy himself claims he isn't a hero. If we're using terms like hero and villain the World Government would be villains, the Revolutionaries would be heroes and Luffy an anti-hero. There would be heroic figures in the Marines like Koby, Fugitora and Smoker but because they uphold an unjust system they aren't heros either until they take up arms against that unjust system.
Huh? Garp has any opportunity to do that right there right now in Marineford. Hes not that tired during the war. He could just blast Shanks off if he wanted but he chose not to. The same like other admirals and finally came to Sengoku himself to which he agreed with shanks to stop the war
Garp may want Luffy to be a marine but he would never stop his grandson dream. I mean with how powerful he is shown in the latest chapters he can easily catch Luffy during the pretime skip throw all his friend in jail and make him be a marine to save his friends but no he didn’t cause as much as he hates it deep down he knows being a marine just isn’t his grandson dream
@@Decade_of_the_DawgMaybe so that part of the Marines still has a non corrupt section which would be Garp and his crew. In his POV, sure the system is corrupt but there is still a need for order and a system that protects civilians. At the end of the day normal people still get caught up in the mess and who else is there to help them? Most pirates don’t help, that’s not their job. The only ones left for that are the non corrupt Marines.
i want to be a criminal so my grandpa who was in police didn't stop me cause it is my freedom i mean this criminal thing is not suited for pirate etc. but you can't give this explanation. i think their is more to it, he grew dragon and luffy, both are yonko level now, i mean grap is doing something big well i didn't read manga idk wtf happen with coby
Shanks is a stabilizing force in the one piece world, and garp knows it. He is in good enough standing with the word government to get a meeting with the gorosei, he had the influence and power to stop Kaido from from joining in at the war at Marineford, and then proceeded to stop that war. Garp isn’t so stupid as to try and take him out. Blackbeard on the other hand is… Blackbeard.
Another thing is that Garp and Shanks are actually very similar in terms of how they use their power. They both value peace above everything else. If they wanted to they could cause _serious_ damage but they choose not to act unless it’s to maintain relative peace, and fostering the new era
I personally go by the theory that Shanks is a World Noble and while Garp may dislike them, he's responsible enough of a marine to not actively attack them.
Put it simply, garp is allowed to save koby as marine,officially since koby is a marine. But same doesn't goes for luffy and ace since they are pirates
Garp's actions to go after Blackbeard to save Lobby essentially passing down the torch can be considered similar to Shanks padding down Roger's straw hat to luffy
We need a Garp backstory. Obviously he HATES pirates, yet he is a "D" Clan member. Most of the members are pirates because they're the most free super power. So.. Why is he a Marine? Even Saul wound up turning on the Marines for Robin, a child he barely knew. Yet Garp is a staunch Marine.
My theory is Garp joined the marines just to keep an eye on his family and protect them. Kinda like Itachi from Naruto joining the Akatsuki, but always putting the leaf village and his little brother on the pedestal. That's the vibe I get.
Because Shanks is ODA himself keeping the Cast in order. Shanks is the equalizer to everything. He is Merry, Handicapped (Appearing to be weak in Mihawk Eyes), Forgiving, A lush, Morally in the Gray… But above it all.. He is a Pirate. Which means he is equally the opposite of all those things.
Wano at the end I can confirm there are major problems with one piece writing I mean the story goes great but plot holes Like marineford like everyone had their haki turned off because Luffy might see and wonder what that is like do some Justice to whitebeard and ace
There’s a difference between saving someone who’s been captured and going after someone you felt was a bad influence on your kids kid. If Shanks had taken Luffy with him like Luffy wanted you can bet your ass Garp would’ve gone after them.
i feel like garp saw shanks as a nephew. its like an uncle and nephew situation. well he raise ace the son of the pirate king by then i think Garp is very close to every one on the ship.
One of the things I really like about the world building of One Piece is that the culture of their world revolves around the idea of “set sail and decide your own destiny. What ever happens is your own responsibility.”
I think a better explanation would be that Garp can clearly distinguish between Shanks and Blackbeard like we audience do. Also, intentions that Shanks and Blackbeard showed in the war were wildly different, Shanks wanted to end the war while BB was causing havoc. Shanks being a Yonkou was a cherry on top!
Will point out that Garp also respects the man in some capacity in general as in a flashback from the Uta incident, Sengoku and Garp grieved over the situation and said that Roger would have been disappointed.
@@SmartAss4123 nah, if they pulled on a single yonko at a time they would definitely take them down unless it's Blackbeard who would probably just run away
Bro Garp knows whats up, he knows that Shanks is on his side. Remember that his best friend was his best enemy and the king of pirates. He's THE man capable of understanding that Shanks is a good guy.
I think Garp is actually greatful to Shanks for Saving his grandson . But like we all know Garp never really showed his feelings completely. Even he was happy, when luffy's bounty raised and He was all known to all . When in the marines everyone was talking about luffy , Garp just smiled a little and said that," he still have a long way to go ." So yeah.
This is simple. Garp knows what Luffy currently is. He knows Luffy can fend for himself and more than likely, that his crew are strong enough to support him. Along with the allies of the Straw Hats. This is literally the best series I was ever invested in. It's story will be Legendary, once it's over with... Also... Koby is still learning and still training. I really hope Garp isn't dead, but... I can see Blackbeard keeping him alive, as to have leverage over Luffy/The Straw Hats, later on.
I agree with most of what you said but I have to mention shanks is only been a yonko for about 6 years now so the going after a yonko is a major thing excuse does not fly for those first six years everyone loves to forget that those years existed when shanks was not a yonko
Garp can't be mad because he either blames dragon or himself for not being in luffy's life. Also when roger got captured, maybe he shared the secrets of the world with garp and now garp understands the will of D better than anyone else that is alive in one piece.
Garp may be the 3rd piece in the powerhouse trinity that was Roger, Garp and WB, and yea even in his old age he's strong enough to do some serious long lasting damage to Shanks if they fought, even if he ultimately loses, but he's not stupid. He dislikes that Shanks had an influence on Luffy, but he also understands that influence was the lesser of two evils. Thats why Garp doesnt actively hunt the Straw Hats for aiding Luffy in his pirate journey, or hunt characters like Marco for aiding him. He knows who the bad guys are, and who the people that just want to be free and chose the pirate route. Both types are criminals, but only one type is actively pillaging, murdering, and causing mass terrorisim.
Also mention at the moment for all we know shanks is technically a celestial…. His dad or grandpa is definitely Garland and because he was found in a chest he didn’t leave like doffys family so he shouldn’t be stripped of status like they were
Also Garp fights Blackbeard after Ace's death. A lot changes after Ace's death. Not only inside Garps consciousness and code, but also otherwise, for eg. SWORD is established
There is a possibility that with some revelations in the current arc in the manga that Shanks could be the offspring of the Celestial Dragons. If Garp knows this there is nothing he could conceivably do unless he was given the orders by The Five Elder Stars. Heck that explains while he was allowed to take Whitebeard and Ace’s bodies.
garp knows firsthand luffy was bound to go down two paths, judging how both his grandsons have rebellious lineages his shanks blame is probably unserious, he knew wat was up
Glad shanks made luffy into a pirate like him and not someone like Blackbeard 😄😄😄
I actually think it was Vivi that made Luffy more into a pirate like Shanks. Vivi kept Luffy's anger in check and kept him humble. Without vivi, Luffy would be closer to black beard sometimes
@@thenexus7343I think he would be more like Kidd than blackbeard tho
@@apenasosky2521Yeah, luffy being like a BB is nonsense
@@apenasosky2521Yeah, Kidd is more ruthless but he has lots of the traits Luffy has
@@thenexus7343vivi is also the reason why luffy rizzed up boa😂
I don't think Garp hates Shanks. Its more like "Damn that Shanks"
That's still hating but not to the point of fighting
@@irrelevanttroll3312I'd say more contempt than hate
@@sharkplay1261 makes sense
@@sharkplay1261like garp and wb, sengoku and wb, wb and roger and so on
Its more like timmy turner’s dad and dinkleberg
Far as the story goes, Shanks was the dude keeping the balance, putting rookie pirates in their place and the warlords and other Yonkos at bay.
Perfectly said.
Well said!
Facts, Shanks is the Pirate God
And he gave up his arm to keep Garp at bay.
That's wb bro .
But yeah shanks also layed a part .
What if Garp knew that Shanks was a part of Roger's crew and he knew that Shanks would never harm anyone unprovoked, much like how no one goes after Rayleigh.
On top of that, Garp probably knows that Shanks gave up an arm for his grandson. So, while he probably dislikes Shanks for influencing Luffy, the way he did Garp has undeniable respectful Shanks at the same time.
What do you mean if he knows? Basically everybody know
@@TVmantitan779well ofc garps knows that. Luffy kept talking about it again and again when he was young. On top of that garp can’t go after shanks alone or well , we saw what happens when you go after a Yonko alone…
@@Gaurav_kattagyangarp is stronger than shanks back then. There's high probability that garp knows his fruit back then, and the reason why the awakening of his fruit will be the only way to reach one piece. They're both risking it all for the comeback of joy boy.
@@himgoat_999 Shanks still had a full crew of high level people, they called the most well rounded yonko crew for a reason, even if they were weaker than now a days, they didn´t exactly threaten Luffy like Koby is threatened by being a prisoner and yeah Shanks sacrificed his arm for Luffy, how people come even to compare those circumstances is a misterry to me.
Garp reminds me so much of Uncle iroh The only difference being is that uncle iroh left while garp stayed.
What do you mean? Iroh was there for Zuko till the end.
@@christianephrem160he meant the organization (being fire nation and marine)
@@naganut9718 oh makes sense now thanks. Iroh chose family before honor!
@@christianephrem160There's nothing honorable about the world government.
@@nyikomaswanganyi5983 I mean Iroh left his honor as a warlord behind to stay with his nephew.
What Garp did for Koby is probably supposed to be connected to what shanks did for Luffy as well, with them both being passing the torch to the next generation and all that
I think the easiest way of answering this is Blackbeard is clearly a Villain's Villain but Garp is a fan favourite hero fighting another fan favourite 😂 Oda probably got tempted but though nah I won't go there... they can dream of the outcome instead 💀
You realize they're all still the villains. Luffy is a bad guy. They're pirates.
The marines are the good guys.
And if a marine slaughters innocent people, he's still good, like axe hand
@@arthurramirez5665you clearly have not watched one piece 💀
@@arthurramirez5665which one piece are you watching bro? Marines are literally the most corrupt organization, and they are literally controlled by some unknown celestial dragons who do injustice to the society,and those celestial dragons are controlled by 5 elders,who are also corrupt to an extent and moreover they were the one's who created the void century
@@Bl8zeyTechnically he's correct but legal doesn't equate to moral.
The Straw Hats are protagonists and Luffy himself claims he isn't a hero.
If we're using terms like hero and villain the World Government would be villains, the Revolutionaries would be heroes and Luffy an anti-hero.
There would be heroic figures in the Marines like Koby, Fugitora and Smoker but because they uphold an unjust system they aren't heros either until they take up arms against that unjust system.
I can still see Garp, chasing down Shanks. But Shanks, not wanting to deal with the headache that is Garp, just runs away
Huh? Garp has any opportunity to do that right there right now in Marineford. Hes not that tired during the war. He could just blast Shanks off if he wanted but he chose not to. The same like other admirals and finally came to Sengoku himself to which he agreed with shanks to stop the war
It's because order from gorodei's order
Also, the thing people are missing Coby is a Marine.
And Garps protege.
Garp fought against Roger several times, it is very likely he saw young Shanks and Buggy hanging around and felt some sympathy for them.
If Luffy ever become a Marine, he would quit afterwards anyway due to all of the codes. That would be an even bigger disgrace to Garp
He wouldn't quit lol. Once luffy has decided to do something he doesn't quit for silly reasons.
The only thing is that he'll do things his own way.
Garp may want Luffy to be a marine but he would never stop his grandson dream. I mean with how powerful he is shown in the latest chapters he can easily catch Luffy during the pretime skip throw all his friend in jail and make him be a marine to save his friends but no he didn’t cause as much as he hates it deep down he knows being a marine just isn’t his grandson dream
Garp also hates the world government. Why go after his grandson when luffy is doing his work for him by taking out the warlords and yanko.
@@Decade_of_the_DawgMaybe so that part of the Marines still has a non corrupt section which would be Garp and his crew. In his POV, sure the system is corrupt but there is still a need for order and a system that protects civilians. At the end of the day normal people still get caught up in the mess and who else is there to help them? Most pirates don’t help, that’s not their job. The only ones left for that are the non corrupt Marines.
i want to be a criminal
so my grandpa who was in police didn't stop me cause it is my freedom
i mean this criminal thing is not suited for pirate etc. but you can't give this explanation. i think their is more to it, he grew dragon and luffy, both are yonko level now, i mean grap is doing something big
well i didn't read manga idk wtf happen with coby
then akainu personally kills luffy due to being the sun of dragon
Garp is also actually extremely proud Of Luffy for deciding to Chase his dreams. Regardless of him.
Shanks is a stabilizing force in the one piece world, and garp knows it. He is in good enough standing with the word government to get a meeting with the gorosei, he had the influence and power to stop Kaido from from joining in at the war at Marineford, and then proceeded to stop that war. Garp isn’t so stupid as to try and take him out. Blackbeard on the other hand is… Blackbeard.
Another thing is that Garp and Shanks are actually very similar in terms of how they use their power. They both value peace above everything else. If they wanted to they could cause _serious_ damage but they choose not to act unless it’s to maintain relative peace, and fostering the new era
Shanks is balance in the One Piece world. Weird how everyone just stopped due to shanks saying that the war on Marineford was over.
Well yeah the marines would not want to fight shanks right after all the damage whitebeard did
I personally go by the theory that Shanks is a World Noble and while Garp may dislike them, he's responsible enough of a marine to not actively attack them.
Garp just went "it is what is."
Put it simply, garp is allowed to save koby as marine,officially since koby is a marine.
But same doesn't goes for luffy and ace since they are pirates
Garp's actions to go after Blackbeard to save Lobby essentially passing down the torch can be considered similar to Shanks padding down Roger's straw hat to luffy
We need a Garp backstory. Obviously he HATES pirates, yet he is a "D" Clan member. Most of the members are pirates because they're the most free super power. So.. Why is he a Marine? Even Saul wound up turning on the Marines for Robin, a child he barely knew.
Yet Garp is a staunch Marine.
Being a "D" doesn't point you towards being a pirate, or being anti-Marine, it points to you being a threat to the World Government.
My theory is Garp joined the marines just to keep an eye on his family and protect them. Kinda like Itachi from Naruto joining the Akatsuki, but always putting the leaf village and his little brother on the pedestal. That's the vibe I get.
Because Shanks is ODA himself keeping the Cast in order. Shanks is the equalizer to everything. He is Merry, Handicapped (Appearing to be weak in Mihawk Eyes), Forgiving, A lush, Morally in the Gray… But above it all.. He is a Pirate. Which means he is equally the opposite of all those things.
Wano at the end I can confirm there are major problems with one piece writing
I mean the story goes great but plot holes
Like marineford like everyone had their haki turned off because Luffy might see and wonder what that is like do some Justice to whitebeard and ace
Foosha Village is Garp and Luffy's home. And Foosha Village is Shank's territory.
The most obvious reason is because shanks was an apprentice of roger(garps rival and best friend)
It is not it. Shanks is a pirate of his own. And remember, Marine wont let anything tied to Roger alone.
There’s a difference between saving someone who’s been captured and going after someone you felt was a bad influence on your kids kid. If Shanks had taken Luffy with him like Luffy wanted you can bet your ass Garp would’ve gone after them.
Ayo... This was the best explanation I've heard for anything in my life
Shanks sacrificed his arm for Joyboy investment: 😐
Shanks sacrificed his arm so Garp doesn’t attack him: 😜
If garp ever meets shanks in a peaceful setting it'd be great if held out his hand and said "thank you for saving my grandson"
shanks is a celestial dragon and probably Imu himself. he triggered the events to get to the one Piece.
i feel like garp saw shanks as a nephew. its like an uncle and nephew situation. well he raise ace the son of the pirate king by then i think Garp is very close to every one on the ship.
Your personal moral code should always supercede whatever the moral code of the group youre in is. Garp is a shining example of that philosophy.
One of the things I really like about the world building of One Piece is that the culture of their world revolves around the idea of “set sail and decide your own destiny. What ever happens is your own responsibility.”
I just thought they were both apart of the ‘Haki Only’ club and couldn’t attack each other.
Also you can’t forget, like father like son
I think a better explanation would be that Garp can clearly distinguish between Shanks and Blackbeard like we audience do. Also, intentions that Shanks and Blackbeard showed in the war were wildly different, Shanks wanted to end the war while BB was causing havoc. Shanks being a Yonkou was a cherry on top!
Will point out that Garp also respects the man in some capacity in general as in a flashback from the Uta incident, Sengoku and Garp grieved over the situation and said that Roger would have been disappointed.
Your english teacher is proud of you
Probably Roger already told Garp the fate of Luffy from the very beginning
Garp didn’t want that smoke, let’s not sugar coat it
Fighting the yonko.
Okay. Who's got a suicidal death wish.
The budget for the episode when Galaxy impact will be shown gonna go sky high
Shanks is one of the few pirates that isn’t settled on an island and easy to find.
I feel like Oda would just answer: “Because Garp didn’t feel like it”
A little correction:
The music in the background isn't from Fukashigi no carte.
It's actually from Monogatari series named Sutekimeppou.
Grap probably knows shanks as he was on Roger's ship
Its like what koby said in the live action. "Luffy has always been a pirate."
Shanks probably helped in Luffy's Village from time to time... so like it adds to that.
Navy can't just attack the yonko whenever they want because they are needed for balance.
And they wouldnt succeed even if they did.
@@SmartAss4123 nah, if they pulled on a single yonko at a time they would definitely take them down unless it's Blackbeard who would probably just run away
Bro THIS VIDEO IS AWESOME 🔥🔥👍
plot convenience 💁♂️
Bro Garp knows whats up, he knows that Shanks is on his side. Remember that his best friend was his best enemy and the king of pirates. He's THE man capable of understanding that Shanks is a good guy.
Shanks didn't take any marine hostage. Blackbeard did. And Koby was Garp's student. Huge difference.
One Piece is really good showcasing the Government that protects the corrupt and the Pirates the are not actually criminals (some)
Garp knows all about the 100 year void and everything else Roger learned on raftel. he knows about nika, etc.
Same reason he jus stood by and let ace die . He's a coward
Everyone with devil fruit powers just needs a life jacket 😂
What if he just wasn’t on the island at that time
Well it’s also the difference between attacking someone you don’t like vs attacking someone for kidnapping your subordinate
I mean I'm not fighting a dude who can make an admiral kneel for how strong his conquerer haki is
Tbh, I think its his way to give respect to a man that gave his grandchild a goal or a role model to look up to.
I think Garp is actually greatful to Shanks for Saving his grandson . But like we all know Garp never really showed his feelings completely. Even he was happy, when luffy's bounty raised and He was all known to all . When in the marines everyone was talking about luffy , Garp just smiled a little and said that," he still have a long way to go ." So yeah.
This is simple. Garp knows what Luffy currently is. He knows Luffy can fend for himself and more than likely, that his crew are strong enough to support him. Along with the allies of the Straw Hats. This is literally the best series I was ever invested in. It's story will be Legendary, once it's over with... Also... Koby is still learning and still training. I really hope Garp isn't dead, but... I can see Blackbeard keeping him alive, as to have leverage over Luffy/The Straw Hats, later on.
That galaxy impact is impressive
Shanks: oh and btw I'm a celestial dra
Garp: say less🗿
I agree with most of what you said but I have to mention shanks is only been a yonko for about 6 years now so the going after a yonko is a major thing excuse does not fly for those first six years everyone loves to forget that those years existed when shanks was not a yonko
So… I just realized, when you talk, every word sounds like it’s that last word one could possibly say on a long breath that is about to end
You forgot to mention that Garp hates how the world government is ran and believes Luffy might be able to change things.
I don't think he holds anything against shanks garp has mentioned on a couple of occasions how proud he is of his grandson
Shanks giving up his arm for luffy is reason enough tbh
Its also because Shanks is a celestial dragon that mades sense with his Connections to the world goverment
I always thought it was simply because Shanks did not kidnap ruffy, but blackbeard kidnapped koby...
I am certainly sure, that noone besides shanks crew even has knowledge about how shanks lost his arm
Lets also remember it seems like most know shanks is a pretty good guy
I’m pretty sure luffy was talking about wanting to be a pirate since before he met shanks
Garp can't be mad because he either blames dragon or himself for not being in luffy's life. Also when roger got captured, maybe he shared the secrets of the world with garp and now garp understands the will of D better than anyone else that is alive in one piece.
I always say this. Oda confirmed in an sbs or interview that Luffy always wanted to be a pirate, he never wanted to be a marine, even before Shanks
Now we know its because shanks is a celestial dragon, one of the highest ranking, and has been driving the story fwd.
Garp is pulling a shanks
Garp may be the 3rd piece in the powerhouse trinity that was Roger, Garp and WB, and yea even in his old age he's strong enough to do some serious long lasting damage to Shanks if they fought, even if he ultimately loses, but he's not stupid. He dislikes that Shanks had an influence on Luffy, but he also understands that influence was the lesser of two evils. Thats why Garp doesnt actively hunt the Straw Hats for aiding Luffy in his pirate journey, or hunt characters like Marco for aiding him. He knows who the bad guys are, and who the people that just want to be free and chose the pirate route. Both types are criminals, but only one type is actively pillaging, murdering, and causing mass terrorisim.
Also mention at the moment for all we know shanks is technically a celestial…. His dad or grandpa is definitely Garland and because he was found in a chest he didn’t leave like doffys family so he shouldn’t be stripped of status like they were
100% agreed u said that very well👌
Imagine Shanks turning out to be manipulative like Aizen 💀
Also Garp fights Blackbeard after Ace's death. A lot changes after Ace's death. Not only inside Garps consciousness and code, but also otherwise, for eg. SWORD is established
If garp went to claim shanks head it wouldn’t end well
Bruh the only thing u had to say is that Garp is a pirate in a marine uniform
Garp has to know that Shanks is a Figarland and royalty*
Garp as too much respect for Rodger and Shanks to bother.
I still would have liked to see an interaction at Marineford between the two
I think it’s because of Shanks celestial dragon heritage
Suketti meppou man of culture
W doron as always
Harp just wants luffy to make the right choices and be a good man
There is a possibility that with some revelations in the current arc in the manga that Shanks could be the offspring of the Celestial Dragons. If Garp knows this there is nothing he could conceivably do unless he was given the orders by The Five Elder Stars. Heck that explains while he was allowed to take Whitebeard and Ace’s bodies.
That is crazy for them to compare what happened with blackbeard
Although he dislikes luffy is a pirate he loves his grandson simple
garp knows firsthand luffy was bound to go down two paths, judging how both his grandsons have rebellious lineages his shanks blame is probably unserious, he knew wat was up
If Garp attacked Shanks at Marineford it would've started another the Marines couldn't possibly hope to win.
it's safe to say that Garp,Shanks,Ace,Sabo and maybe Dragon, know about luffy's true dream when it was reveales to us and his crew after Wano.
Or...garp knows that shanks is a different beast that you gotta be in your prime to fight