And you have a problem here.
Game can't be balanced for 1v1 games AND 4v4.
Not with asymmetrical factions that have different strengths on different game phases, because strengths and weaknesses will always be enhanced by the number of units/players.
There is no way around that.
This is true, especially with the way Soviets are designed. Why Relic decided to put a faction that is literally supposed to defeat the enemy combined arms relying on solely half of their tech tree is beyond me (you can backtech to T2 but isn't always feasible and you simply can't have both T3 and T4).
This implies that half the Soviet tech tree, in a balanced 1v1 state, must be equal to the whole of the Ostheer tech tree (although I suppose T4 Ostheer isn't really viable in 1v1 so there is that factor). Check out what happens when you switch to 2v2 with that logic.
This effect does disappear in larger games but is very apparent in 2v2 (think 1CP Guards+Shocks last patch or T34+SU85).
What happened to that one idea where people suggested a cheaper cost for Soviet backteching (build T1/T2 for regular price, build the other for a cheaper price, same with T3/T4)? This would allow the game to be balanced a hell lot easier for more modes I feel as the 1v1 experience would not be so jarringly different from the team games where Soviets actually have access to all of their tech tree (it'll probably lessen a lot of the balance bickering too as 1v1-only players have a huge difference in opinion and ingame playstyle to teamgame-only players to players who play both).