I think you should pull out out A&A europe or pacific (the orginal ones), they are imo much better from a balance standpoint and have the best utilization of the convoy system. You could add that as a base and then add some cool stuff like tech, more lend lease, combined allied attacks, etc. And in those games turn 1 isnt as formulaic. At the beging of the europe game for example each side get 12 ipcs to spend and place them along with the other starting units… Allies can split it or spend it in one place. You have soo many options as to what you want to do with that.
Now how would I design a&a? Make a global version of the classic europe and pacific games, along with additional improvements on convoys, tech, multinational attacks, add a morale system, and overhaul some units that need it like aaguns. All the while try and make it as simplistic and smooth as I could.
