If it isn't running on the simulation thread, and if it would be using currently unused processing, then it is probably fine

@Eilat I recommend you to have a look at the game Earth 2150. It's near futuristic war and the way it deals with supplies is great, the best I've seen yet never found it in another game. Size of maps shouldn't be an issue if you concentrate on particular missions as part of a larger campaign map, for which there are also projects around.

We'd have to look at the details, but your opponent probably sniped your archers while your archers overkilled other units.

Creating large maps is easily done by importing a large sized heightmap, I’ve done it many times, the scale far exceeds giant size.

Also worth noting that if you scale everything to a factor two, your map is twice as big