HV has it. In first month AI is aggressive but when this time pass it sitting in own castle and is doing nothing.And doing stupid things, in previous instalments, is a petty offence compared to NOT DOING ANYTHING AT ALL. I am talking about the AI suddenly stop doing anything and just passing the turn, until some unknown trigger wakes it up. Not even H4, had such problems which was shipped unfinished.
Also in HV AI is cheating like hell - it never fight with neutral armies, just go near them and enemies are gone, not losses at all for AI. IIRC it also have a huge amount of resources income.
The problem with HV and HVI is that AI desing was last step in game creation instead of focusing on it all the time from begining. If these game were design around AI at first place, not graphics, then maybe we will have at least descent computer opponent.
Well, maybe I played too much in GalCiv so my vision of game AI is"corrupted" by these games.