It would be awesome if you could incorporate buildings for cities, trade, and the construction of vehicles.
•Fortresses - These would enhance defense against rival nations.
•Recruitment centers - These would allow for an increased workforce to recruit additional units.
•Shipyards - These would be used for trading or constructing navies.
•Factories - These would produce steel, motors, aircraft components, and oil for vehicle manufacturing, as well as enabling trade for currency or various resources.
•Uranium enrichers - These would be utilized for nuclear weapons production.
•Monuments - These would provide beneficial effects that could be advantageous.
Additionally, it would be great to introduce military and civilian leaders with unique buffs, as well as a messaging system to communicate with other AI nations, and you ask them for peace, war, etc., and they can refuse or accept with a sentence, and also nations could chat with other AI nations too, which could be disabled in the settings if desired.