You know, it seems the game is very unbalanced at the higher levels.

The valor boost most enemy units recieve means even medium level units can give your top-of-the range men a hard time.

Example

I decided to run a brief test, and had a unit of billmen take on chivalric men at arms at normal.

I played the CMAA, and 3 out of 4 times the CMAA defeated the billmen who, whilst a good unit, cannot compete in hand-to-hand fighting with the tougher men-at-arms.

To my suprise, on expert and hard it was the CMAA who died. When I switched roles and went the billmen, it was I who was soon getting killed, not the CMAA.

This discovery explained why battles on expert generally went badly even against inferior units, especially on occasions where I had a general with a superior command rating, had soldiers who were quite fresh, and was fighting at the top of hill.

Playing the game on normal means that it is not less difficult, just more fair, and infinitely more enjoyable.