Only when u retreat too late or are really unlucky.
They can easily spam mines against axis who lose models due to tripwireflare on 4 men squads and mines. They can't really have a sweeper on both sides of the map all the time. Also they have many counters to static positions - flame stuff mainly. Basically they are a bit OP in this region in 1v1 setup. We probably won't agree but it is ok.
The dps esp of ost is generaly a lot higher then sov cuz of 6 men squads. Soviet dps is mostly a lot lower cuz of the 4 men squads of ost. Ost generaly wipes 6 men faster then soviets wipes 4 men squads due to soviets lacking powerfull nades and ai upgrades and actual good ai on main guns of tanks.
This is the reason soviets suffer more model and squad and vehicle losses they are designed this way. Not just that they retreat to late. They face stronger firepower throughout the game, retreating with 3 models out of 6 still has a bigger chance getting retreat wiped vs ost then with 2 men vs soviets.
Soviets can spamm mines but they wont wipe anything you always need to follow up. Ost doesnt need to follow up every time but when they do its with less effort. But the mines are more costly.
I see no issues here that is imbalanced. You keep trying to paint soviets op while they clearly are not.