You know, COH one had a funny tech for their riflemen. Can't remember if it reduced their upkeep or just the population per squad.
Might be worth while to implement a similar solution.
I don't think this would be a viable solution
In coh 1 every faction had Global upgrades, you decrease your field presence temporarily to improve All your troops combat capacity permanently, german vet, USF supply/bars, PE fieldcraft, vet gain ect.
Such a system does not already exist in coh 2 and i do not expect this to change.Unless they pretty much redesign the entire game, They just have munitions upgrades which are a per unit improvement not global