Kob, maybe you could go with multi-events files, that change the availible builds, ala Red Front?
That would give you EVERY slot to use again, and some could be the same for both (AT gun, AA, ships, ect).
Germany, Russia, and the Allies withdrew obsolete units as the war progressed, so this wouldn't be unrealistic, and you could add things like Improved shermans (the 76L version, or the easy 8), more tank destroyers like the M-10/M-36, maybe mobile artillery like M-7 Preists and German Wespe or Hummel, or perhaps the Elephant and Hunting tiger TDs, maybe motor infantry for allies and Russians, P-40s, later versions of BF-109s, and so forth.
Also, I would like the P-38 to never go obsolete, the allies used it till the war's end, and the P-51 is still to short ranged (a p-38 can fly 40 squares, a P-51 only 16! This is inacurate, the P-51 had nearly the same range, inferior, yes, but not by a wide margin)
Would love to see French equipment, and an end to commandoes.
Having the Neutrals and independants having first line Aircraft and Tanks is extremly unrealistic.