I discussed in this thread: https://forum.paradoxplaza.com/foru...yeren-is-the-ai-biased-against-humans.840108/. Ganging up on Yeren right from the start makes sense. Haixi attacking Yeren ahead of Jianzhou when the latter has had its army and economy wrecked (neither had allies, both were Haixi's rivals) doesn't. The issue was that the AI would attack me even though it was vastly more beneficial for them to attack the other AI, as it would have been a far easier fight that would have left them with higher tax same religion land, instead of piss poor wrong religion land. And the behaviour wasn't a one off, I restarted several times and exactly the same thing occurred. If the Ai isn't biased to attack humans, then its decision making in situations like that is poor. To be fair, I do suspect it's the latter as I don't see any reason for Wiz to be lying about this.
I remember that thread. I actually tried Yeren out about 2 weeks ago, and just like you I got double-tapped. Similar to you I first had to fight Jianzhou + Korchin and then Haixi. That took some pathing abuse to get done and make Haixi a vassal. It's important to improve with Ming though so they don't go pissy outraged mode and warn you too early. This behavior isn't unique to the human there though; Yeren always gets dogpiled. I'm not sure why the AI is idiotic in this regard but it seems to prefer off-religion land and suicide in the general sense (just check out the length of war thread) so par for the course I guess.