1. Victoria + Hearts of Iron = great game!
2. Map: covering the whole earth, with no provinces (cities, borders could be as points with coordinates), with road, railway, with more extensive terrain...
3. Units: consisting of people of a particular nationality ,more complex, forming a own garrisons, having concrete numbers of guns, rifles, ammunition, food and other, with more complex structure including the battalions and companies of various types of weapons...
4. Industry: factories producing specific types of goods: tanks factory, ammunition factory, small arms factory and other, food processing industry...
5. Combat: all units should have their own areas of action, should be additional orders like: storming city, besiege the city, ready to defend and others...
I will prepare a few simple "screens" for my ideas.
Besides, what we want? Just look at the reality and copy it to the game.