One thing you might consider in this situation is building walls of dragon's teeth across the front of the canyon walls. Spiders can climb canyon walls, but they cannot pass dragon's teeth. You can also build dragon's teeth on extremely vertical surfaces. For under 150 metal, you can basically deny both of the outer 2 clifftops, and then the spiders must either grind through your dragon's teeth, or they must fight through the canyon, and while they are on the dragon's teeth, they can be flanked by a sortie. And if you do this, you don't obstruct passage in the canyons themselves, at all. Another fun trick is to just start airlifting tanks up to the canyon tops. If they can't control line of sight, and they can't really use their range, recluses are not good value for cost. Unfortunately, you can no longer carry a bull with a stork, but even so, on a clifftop, a fiend will beat a recluse, and they really cannot fire onto high ground from low ground as their rocket trajectory is absolutely terrible (basically, they fire their rockets slightly upwards, and then the rockets transition to almost a flat trajectory shortly after launch, meaning it's basically impossible to lob them onto anything you don't have direct line of sight to). (interestingly, this is also why their target ground is wildly inaccurate, it's because at the point of impact, the rocket trajectory is basically flat and extremely low altitude, so there is huge variance in where it could contact the ground). I think people massively overestimate the value of static units up on the clifftops, where they have line of sight issues, but massively underestimate the value of MOBILE units on the clifftops, where they have massive line of sight control.
One thing you might consider in this situation is building walls of dragon's teeth across the front of the canyon walls. Spiders can climb canyon walls, but they cannot pass dragon's teeth. You can also build dragon's teeth on extremely vertical surfaces. For under 150 metal, you can basically deny both of the outer 2 clifftops, and then the spiders must either grind through your dragon's teeth, or they must fight through the canyon, and while they are on the dragon's teeth, they can be flanked by a sortie. And if you do this, you don't obstruct passage in the canyons themselves, at all.
Another fun trick is to just start airlifting tanks up to the canyon tops. If they can't control line of sight, and they can't really use their range, recluses are not good value for cost. Unfortunately, you can no longer carry a bull with a stork, but even so, on a clifftop, a fiend will beat a recluse, and they really cannot fire onto high ground from low ground as their rocket trajectory is absolutely terrible (basically, they fire their rockets slightly upwards, and then the rockets transition to almost a flat trajectory shortly after launch, meaning it's basically impossible to lob them onto anything you don't have direct line of sight to). (interestingly, this is also why their target ground is wildly inaccurate, it's because at the point of impact, the rocket trajectory is basically flat and extremely low altitude, so there is huge variance in where it could contact the ground).
I think people massively overestimate the value of static units up on the clifftops, where they have line of sight issues, but massively underestimate the value of MOBILE units on the clifftops, where they have massive line of sight control.
The tip for putting the radar at the hil top is priceless. I forget to do that as canyon front but do it regularly for the canyon front when I am air.
The AIR player in the Blue team was horrible for letting his team get killed for several minutes without defending them.