I know that this is the behavior of easy AI's, but it shouldn't happen with standard AI's. I'll look into it.

Sure, if you want some replay's for research, i can send you some

Was your gaming lagging at all? Was the CPU of one of the players capped? Think this can happen some times if your CPU bound as the AI can not think correctly.

The game usually lags in certain moments in game, however im not really sure about the CPU

AI teammate units not reinforcing (even if you have a half-track, ambulance, or reinforcement structure nearby) is prevalent not just in this mod, but also in the vanilla game and even the recent Winter Balance Preview. I dunno if the AI teammate just "freezes" (while the enemy AI doesn't) because of some error in the AI script, but that's just one of the many ways AI teammates can be downright stupid.

IIRC, there was this one video of HelpingHans having to carry an AI teammate after his human teammate either dropped due to a bad connection or intentionally left the game. (The replacement AI is already on Hard and Hans still considers it stupid... *sighs*)

https://www.youtube.com/watch?v=VT8uwBGzyjs

AI teammates I think also look worse then a foe AI because they don't get imcome bonus because they are on your team and you would get the bonus as well. Without that extra money to float them they can't over run you with units like they normally can.

Tested this with 2 expert AI's. One on my team while I did nothing but fly recon planes. My AI got stompted EVERY time hands down.

The resource bonus is applied per player, not per team. At least that's how the files look like, I didn't test it. We can easily watch the replay and look in the friendly AI's resources.

Hum, I am at a loss to explane why human AI teammates suck then. But they do seem to suck vs all AI teams.

Maybe one reason why AI teammates seem to get more manpower is because they only build a few units (compared to the human player who builds multiple units for combined arms), only building more when either those units get killed, or a certain resource quota is reached.