The better question is, how do you balance units based on cost, when everyone starts with different starting resources?
I don't know, you could for example, give them different units with different prices, different upgrades and different stats, you could maybe even lock them behind different tech structures with different tech prices to introduce different timing?
And in regards to starting resources, menpower specifically, its 500mp minus starting squad, but there are more exceptions to that now and can you guess which factions gets most of these extras?
OKW gets extra 100mp.
Ost gets extra 60mp.
UKF gets extra 50mp.