I think this is an issue on how their limit were set. I noticed that their largest army cap is different depending on the difficulty set (I don’t remember the numbers rn tho). So after reading the post, I think the reason they work better on lower pop cap is because their “agressive state” checks for the population % compared to max pop while the pop limit is hardcoded (as in, if hard = 50 then it’s 50 regardless of pop limit). This would make sense, since if it tries to atk once the pop reached 40% (assuming they have the same amount of vills as army) then if the max pop limit is 200 they’d try to atk once they reached 80 pop, but if their diffic cap is 100 they won’t try to atk if the max pop is set to 300.
The one thing I notice tho, is that at first sight it might look at easy fix: just change the difficulty cap to check for the % of max pop instead, but the problem is how’s the AI coded to macro? if the AI uses the same macro code in all difficulties it means that both moderate and extreme would have a big army really quickly at higher max pop. I actually do feel like they’re a bit worse macro-wise at lower difficulties because of differences of feudal times, but this is something to have in mind when rebalancing it.
On the other hand
Something I noticed that improved a lot in this AI is doing and dealing with rushes. On HD I could easily steamroll the AI with some archer rush, but in DE I think even at moderate they’re much better at defending from rushes, in fact it was a huge annoyance for me to be able to keep the pressure, they were continuously baiting my army to go under TC fire and it actually ended up going castle before me, so I ended up having to rush some spears since they started sending knights to atk my skirmishers. Trying to rush the AI and keeping pressure imo was a lot of fun, things only got easier once I managed to get some rams ready to destroy their TCs. And all of this makes sence with the pop limit thing, when you try to rush you’re going agressive with a smaller army, which means the AI will have a much better chance to fight back, have even fights and maybe even push back.