Idea is simple and does not replace the current system, it's just something you can pick.
Imagine picking europe and then making sure "advanced world domination" is checked. What does this do?
Advanced World Domination:
-Every country will be in it's full glory, with all it's cities (Small towns not included, or would it?),
-You open the country when you click on it.
-Once a country is taken over fully, you can manage the country more easily on the world map when it's about making units etc.
Just a small suggestion that might be fun