[Edratman]

I think you can figure out how much supply a given army requires by moving it into a friendly province. Just note the supplies used in the provinces before and after the move. Of course, this is very little help, if any at all in determining what the supply situation will be when moving into an unfriendly province.

As for modding the game to minimize supply issues I think giving an additional supply bonus to commanders would cause the least disruption to the game mechanics that everyone above objects to. I have never figured out the thematic nature of the commander supply bonus. A lot of commanders, mainly mage types, have supply bonus, and I have never bothered to figure out why.