Feature suggestion

I have played many a call of war game where I can just land wherever I want which, historically doesn't make sense because of supply, adding in supply to the game would add in an extra layer of depth while incentives more players to play the naval game if they can intercept convoys, each province could have a certain amount of supply points which would indicate the max amount of troops you can have in that province, you could have it so if a unit is over seas but has a friendly port they would receive supplies from a "supply route" which ships could raid and negate supply, if a unit did run out of supply then it could suffer attrition and could suffer a penalty to health, how good it is in combat and movement speed.