Total War does this, once your archers run out of arrows they turn in to the game's weakest melee units. It completely changes the strategy of the game. Having supply lines for your war effort is a great idea, but...
And this is where both Age of Empires and Total War let me down when they came out with newer versions. The more you add to the graphics the longer it takes to generate a map, the commercial games answered this problem by making the maps smaller and smaller. They made the maps far too small to really consider any real strategy in the game, they became simple slogging matches for people with short attention spans. I still play the original editions of those games, the newer versions are of absolutely no interest to me.
I have an idea for a feature that should be within the scope of the current development though.
When building houses a "snap to nearest neighbour" type feature would be handy, it would make it a lot quicker and easier to set someone building and keep it neat and tidy.
Cheers,
Andrew.