Quote Originally Posted by Dhampir
I'm not even going to try fighting a battle that big.
I've had stuff like that happen to me also when autoresolving, my casualties exceeding five thousand while the AI got out with nary a scratch.

Generally, an enemy settlement + enemy full stack + autocalc = crushing defeat. Especially if the AI is led by a family member.

Set "allow unlimited men on the battlefield" to true in the preferences.txt to have all your men show up on the battlefield at the same time. So that you can command them personally instead of autoresolving.

Although you'll probably have to lower your graphics settings to avoid a heavy FPS hit.