Could be quite interesting, indeed. Could devise different AI difficulties based on how people actually play the game and the limitations we humans have (e.g., we can only click and see so much at once).
Have a Beginner level based on neural network analyses of actual beginner players. Extreme level based on neural network analyses of top-tier players or close to them actually playing the game. And all points in-between; as well as be able to extrapolate beyond in order to challenge even the top-tier players in a human-like way.
There were conversations in the past about this type of thing. I thought there was an AoE4-specific thread, but can’t find it at the moment. Here are a couple old threads I found that you may like to view, though: