I saw that once in an old microprose game Fields of Glory. The game cast you as an army commander commander at Waterloo and other 100 days battles.

Your corp and division commanders had different degrees of recklessness so youd give your orders and it was always a gamble whether they would be followed or not.

It was a frustrating mechanic at times, most notably once when at waterloo uxbridges corp refused to withdraw after routing a number of french columns. Instead they gloriously charged the rest of the french army........ and died. Horribly. Art imitates life or what :)

It was a nice additioon to the game, but might not work in TW battles as there is only one commander. Perhaps you could introduce a more developed chain of command with captains/generals commanding each wing of the army?