Discussion about the game's artificial intelligence.

2) He sometimes flees, especially when playing on the highest difficulty. I actually prefer that he doesn't flee; it's just annoying to chase him all over the map afterward, especially since he quickly replenishes his army after a defeat.

He flees. And he should flee. Moreover, he flees much more often than he did in the third game. Because winning one battle shouldn't mean losing the war.
My friend and I had the main heroes flee five times per game, and it was fine. As long as the hero is still alive, nothing is lost.
By the way, I liked the "Hit and Run" tactic in the third game when used by the computer.