Idea: Upkeep supply to armies

Here is an idea I had a while ago that I have developed a bit: Small transport trucks spawn in resource provinces and follow the roads to an army where they despawn. These transports convert to ships when going over water. More spawn depending on the number of resources produced by the province. These transports supply the troops with their unit upkeep. Now here's where it gets interesting. The transports will take the fastest way to the army unless it is blocked by an enemy unit that is visible. Otherwise, it will travel the safe route, avoiding the enemy unit. If all routes are blocked, the resources can't get to the army, causing its hp to decline bc of the upkeep lack. This means you can siege an enemy army by cutting off its supplies via blocking ports roads. You will be able to destroy an army much bigger than yours if you play strategically. You can also use the encirclement method to defeat enemy armies. Resources will continue to be supplied to an army until its daily upkeep is met. Additionally, you can use espionage (I haven't decided if it should be military or economy) to disrupt the transport of resources to units.

For Naval, it would be a bit different. Naval fleets have a capacity for how many resources they can hold. Ships would have to return to a port or naval base to restock on resources. If they run out of resources at sea, the hp of the ships decline.

This would make the game more realistic as resources don't just automatically reach troops, they have to be delivered from the individual resource provinces. Resource siege was a common tactic in war such as the Siege of Leningrad and Operation Uranus where resources were deliberately cut off from reaching an army.

Yes this would be a complicated game mechanic, but it would open up a lot of new interesting strategies. You wouldn;t be able to just rush your units out or send a fleet to camp in the middle of the ocean. What do you think of this idea?