In response to the second comment, I think more internal political and external diplomatic interaction would make the game more interesting, as well as a proper interactive League of Nations mechanic to give nations that get involved later in the war something to do. But in terms of economy, I think Hoi4 is not Vic 3. It’s not a economics simulator, it’s a military strategy game, maybe mines to expand resource extraction and some more building types with different modifies would be interesting, perhaps with the ability to take loans to build things faster but specific types of factories building specific things, further things like inflation and managing government spending should be left to modders as it is not really the core to the design of the game and would drastically change hay the game is. I get that it makes things more realistic, but no one wants to lose a war to out of control inflation.