So I've put a little thought into this during a shower and here is what I landed on.
...
Must have been a long shower.
Anyway that actually sounds very interesting, the setting is good as it allows all the iconic WW2 weapons to feature in the game without having to worry about realism implications.
Only significant issues I can see are the different skill requirements and resource gathering/requirements of the factions. Having one faction as a fragile finesse faction with inherent high micro requirements while the other is a durable, easy to play faction poses issues for balance. In low-skill matches the finesse faction will be UP, in high-skill matches it will either be OP or balanced but with higher skill requirement (kind of like how Ostheer is positioned currently).
As for different approaches to resource gathering that is an issue, as many CoH balance problems have stemmed from the fact that factions have interacted with resource points in such different ways, making it basically impossible to get balanced match ups across a variety of maps.
Of course both these issues will exist to some extent no matter what, but branding them into the factions' core design from day 1 seems like a recipe for trouble down the track.