failed #2 | attempting guardin' gnome on expert realism with default bots ( survivors must survive )

A Left 4 Dead 2 singleplayer playthrough but I added a few challenges ( expert + realism + all four survivors must survive + default bots )
Left 4 Dead 2 Expert Realism ( 4 must escape ) with default bots run | The Parish
disclaimer :
I do not have any gameplay altering mods ( the mods I installed was mostly for aesthetic purposes only )