The best small units I ever fought were controlled by the AI. It was my second campaign game, I was England and well into the invasion of Spain. The Spanish king had two stacks in Aragon and one in Valencia which held only two men. So I pitched the best of my army into Aragon and left a stack of "odds and sods" in Valencia to cut off the Spanish retreat. I auto-resolved the Valencia battle.

The two Spanish soldiers (Royal Knights, ex-princes) killed 155 men and routed the rest.

I was so shocked I replayed the battle properly, to see what these War Gods could do. Version two went a little differently. I sent in two units of (turncoat) jinettes, on set on engage and one on hold formation, and both knights went down in a shower of javelins. One of the pinning jinettes died, possibly hit in the back by his own side.

Anyone else seen such variance beteen the auto-resolve and a proper battle?