I do agree with the idea. But for the building part, it’d be better if it was either a) cheap as a barracks or b) the supply are invincible (basically once there’s 2 friendly provinces together a supply route forms automatically). I’d say TB saving units as a air dropping supplies feature would be great would be need to be nerfed. If I had a 10 stack encircled and 10 TBs back at base then they’d be easily brought back to full health. I’d say one TB performing one supply drop shall only recover a unit 20% health. But if there’s more than 1 unit the supplies are dispersed. That’s means if there’s 2 units it’d be 10% for each. For the navy supply route that’s a very great idea but something would also need to be added in order to counter it. So I’m wondering If it will be possible to produce convoys to deliver the supplies. And the convoys will deliver supplies automatically (you’ll set the route for it). For example if you plot a route between Calais and Dover then the convoys will deliver supplies between the ports automatically. And the way to counter this would be to put naval vessels in these supply routes. Convoys shall engage in combat like normal units. Except they bring in maybe about 20 men casualties and a lot of economic loss. Also last thought: it will be great if supply depots had a supply status. Then the real situation of the battlefield will be reflected even better. (Troops are supplies by the supply depot in the province. When supply depots are interconnected they send resources to the front line) For example if you have 20 divisions in a single province then the supply depot will be low on supplies. So the player would either have to upgrade the depot or mover troops elsewhere. I think this can greatly emphasize the connection and relation of supply routes and encirclements.
Edit: units will take a penalty if they are not in a province of a supply depot. It could go like a reduction of 2% Morale every hour.
Thoughts?