Unfortunately the bots are still pistol marksmen and out of all my hits in COOP (while playing CTE) 80% were headshots.
I hope this will get fixed soon, because it is just like someone mentioned here before, it's like playing against a random generator. It doesn't matter what guns the bots are using, it can be an old rusty AK with iron sights from the 60s, or it could be a pistol too, they'll eventually pick you off with a headshot even from great range.
If we could get an insight to how your bots' aiming behaviour works, maybe we could try searching for a solution.
Bots getting shot:
Since weapons in Sandstorm are a lot more underpowered than in the original Insurgency, bots getting shot needs to be properly looked at. Right now I can shoot a bot with a 7.62x51 bullet, his animation does a slight flinch, but he still keeps shooting at me accurately. If you guys won't adjust your bullet damage (and possibly penetration, since I couldn't kill an enemy through a door), you should at least add a wounded animation to the bots.
As of this moment, bots can still sprint on the battlefield, can still shoot accurately even after being shot multiple times.