I was recently in a round where I had Share Map with the whole of Asia. At one point, a couple countries fought another one and it became very confusing as to who owned which territory. I came up for a possible solution to this. If you have share map with 2 countries that are at war with each other, a red line will separate their borders. The territories will still remain green but the red line will separate each countries territories.
“No man is happy without a delusion of some kind. Delusions are as necessary to our happiness as realities.” -Christian Nestell Bovee