The teammate AI, I'm fairly certain, is just the L4D AI. I mean the game is basically a mod as far as I can tell. If you compare the menu screens they are practically identical, just recolored. So yeah, in that case the AI should actually be pretty good. I think the thing to complain about would be the enemy AI which, as far as I could tell, is just the standard L4D zombie AI. Which is great when there are 20 of them coming at you and they serve mostly as a distraction from the special zombies who are your real threat. When they stream in one at a time, it's not exactly challenging gameplay.
