To be fair, I think the Soviets have a lot less to counter a KV-8 with than even the Germans do if you were to manage to steal one
man i steal a KV8 in a 2v2 once... believe me after i repair it enemy pushing with massive infantry (like 8-9 squads) and i roll that monster in, it killed like 30 after chase them back to their fuel point where they got 2 SU85 sitting there, i manage to get my KV8 back to safty and use it to push with my 2 pather and my teammate's 2 panther and p4 to their base, it is like instant win, i see a conscript try to throw out a antitank nade but he just got BBQed before it throw out.