I think it would be great to try Grizz's idea at least once a week. Some of the best times I've had were in the AvA and during the FSO... I attribute that to added immersion/excitement involved when matching wits against historically accurate plane sets. Granted, under Grizz's proposal there could still be P51s, LA7s, and Spits vs. 109s and NIKs (which aren't necessarily "historic" matchups). It's more of a compromise between the AvA and LW arenas.
Why not try it for 1 month? That's only 4 days! At worst it will add a bit of excitement to the current arena schedule.
Regarding the balance issues, that's quite simple:
1. For base taking, make the allied bases capturable with just 5 troops (SdKfz 251 will fill the role of the M3). The c47 can be used for both sides, I don't think that would be too big an issue. Axis C47 would only carry 5 troops.
2. For bombers, perk points can be used as mentioned earlier.
3. I think the tank matchups would be relatively even, but I am not much of a GV'er so I would have to defer judgement to those with more experience.
4. The fighter matchups would rather even
5. The attack matchup would favor the allies with the IL2... but so what? I don't think it would be entirely unbalancing.
My vote is to give it a shot. For the naysayers, I urge you to consider the law of unintended consequences... you may find that you enjoy it after trying it!