I guess if I was in your position, I would use classic game pieces for the new countries:
Old Germans are gray I think, they could be Italians, Old Russians would be good for Anzac. Old UK for India, Old U.S. for China, France could be old Japanese or Fortress America Southern Invaders.
France seldom builds units, in fact all you really need are some infantry for later African moves. Tactical bombers if you do not care could be fortress America bomber pieces, use some helicopters for smaller countries if they need any.
I rarely see many tactical bomber builds. Maybe Russia, and America might build some. Carriers and destroyers are built a lot in my games. Since transports are non combatants in 1940, just use transports as Destroyers, I rarely build cruisers, so just use a battleship with a penny underneath it as a cruiser. Just use paper to represent transports. Not sure if this is a good idea, but mechanized units can be risk pieces or even monopoly houses…
Just a few tips with not too much insight. Hope this helps.