All Soviet do is abusing, exploiting, laming, or lose
That right there is the issue.
If soviets don't have that they lose. While the M3 is a bit to good, i don't think it will change the way people want it to. Aka, it will probably get less durable and less damage but the units in it will still be able to fire.
HTD is actually only broken because the way it interacts with cover. If they fix that it might be okay. (cons without cover on HTD will still lose to Grens with LMG or PGrens).
SU85 is countered by good use of smoke. Almost all german doctrines have smoke, but because german players want to "abuse" current strafe they use a doctrine without smoke.
T70 is a "do or die" unit. If you go for it and don't do enough damage you will get rolled by P4s that come not that long after them and you delay T34 and also only have AT-guns as anti-tank (if you did go for T2).
Also the counter to clowncars and T70s is good use of PGrens with Schrecks though they probably come to late for clowncars but clowncars can be beaten by upgunned AC.
Yes Guards and Clowncars will beat the upgunned AC, but at that time you can have Pgrens out too.
Overall, i agree that there are things broken on Russian side, but it's not like it doesn't go both ways.
I mean, just one example: it takes less fuel for germans to rush out a P4 than for soviets to get out a T34 (without upgrading nades for cons and both sides not building any vehicles). Which is the only reason you will see people rushing for SU85, because it is the only unit that can deal with the P4 rush effectively.