This is they key here. Soviets generally only access 2 of 4 Tiers. Why do Soviets spam Maxims, Snipers, Scout Cars, Penals, etc? Mostly because Conscripts scale worse than any other factions infantry. The faction is designed to limit combined arms, and this idea would deepen the limitation.
+1.
back to OP...
different exponential values are too complicated. and you get punished for having two of the same unit?
con spam, penal spam with guards, maxim spam, "sniper spam (2 snipers)", m3 spam are supposed to be viable strat options IMO... yes, as many do think, some of those options maybe too good (i'm not saying anything), but that does not mean you nerf the spams by just punishing one faction EXPONENTIALLY over the other.