The problem with soviets currently is that con spam is the only effective build they can do at the highest level. This is countered by ostruppen tech builds (haven't played any since the patch but they where last patch) and assgrens; as well as just good German play.
At the end of the day con spam is completely one dimensional and you pretty much know what is coming and it is just a race to see who gets tanks first. soviets can mix in a doctrinal unit like guards, shocks, 120mm instead of getting a 5th squad, but really getting anything out of your buildings before hitting t3 make any sense compared to the above options because it is likely to be countered as soon as it hits the field, and even if it isn't countered. Rarely does it have much more impact then adding another con squad or geting a doctianl unit instead.
Make it so Germans and soviets don't both basically hit the same timing if they go four units tech or make it easier to get tech buildings (T1 and T2) before 4 cons for soviets and soviets will be fine.
Yeah I think this is the worst part of playing soviet. The game only gets interesting after the first 3 or so minutes when you choose t1 or t2. It's not a balance concern for me as much as one of entertainment.
Making t1 or t2 come sooner will introduce balance issues which will need to be corrected, but overall I think the game will be better for it.
Other than that I don't really have any issues with going soviet.
@OP you would have saved a lot of confusion if you didn't talk about late game units in your post.