For me, the enemies in U3 seem a lot more "dumbed down" than enemies in U2.
Enemies in U2 were rutheless and merciless. If you were downed or being choked, enemies would still nade and rpg you and even shoot at you. Also they were more realistic, as in they had stopping power. They slowed down after you shot 'em and headshots were actually head shots.
In U3 the enemies rarely slow down when you shoot at them, and their heads are made out of metal. A thousand shots to the head gets you a head shot. I do like their "still" movement as they bob their heads around which makes headshots harder just like the DF enemies.
Drakes Fortune enemies are the best IMO. Like I've mentioned their heads move about when they stand still and getting a head shot is tricky. They also flank you instead of camping.
I think in future ND co-op games (TLOU and U4 if it's really going to be made) we need much more smarter enemies.
These enemies should have the following abilities...
That's all I can think of for now, but what I'm getting at is more smarter enemy AI's please.
All these smarter AI's will be less bullet spongy yet more tougher but only in Crushing. For me Crushing is Hard mode in disguise with added Revenge Nades, Kickback enemies and clown masks.
These enemies I've mentioned and their features will only feature in Crushing.
Though I agree that the AI is dumb as dirt and needs improvements, some of these things you listed here seem insane. Such as picking up other weapons, reviving each other and throwing back grenades.
Yikes, Co-op would be hell to finish with that!
It's crazy enough with the guys that can snipe you with a shotgun!
This would be great as Crushing+ AI.
Reviving enemies seems a bit...I don't know...forceful in the game's pace and all. All of a sudden, I got surround this guy and I don't have a nade since the enemy threw it back and now he's revived...by a brute. It might be the same as for vehicles...but I wouldn't mind seeing thatt in a Super-Siege.
Oh! Maybe instead of taunting, the enemy AI would possible give some congratulations to the killer. Maybe they could incorporate signals through body language in order express communication between in the heat of the moment.
Also, we have so many styles of enemies, such as Eddy's Pirates, or Lazaravech's Mercs, why not add in some subtle touches in their AI as well... Pirates would be more ruthless and less disciplined. The Mercs would use tactical strategies that are common amongst squadrons...you get the idea...