I just see some massive soviet failing there. They could ve pushed over the battlegroup HQ and panzer HQ with ease.
Furthermore the SU-76 spam is just idiotic once you know they have Tiger Ace on the field.
Also they could ve easily pursued the Tiger Ace with anything, the strafe was providing vision for them.
Besides that he should've just opted for Barrage on their retreat point just after a blob retreat instead of those in my opinion badly aimed barrages I keep seeing.
I think those are pretty minor compared to the amount of squads lost (predominantly by the axis) and those 3 command panthers...