Not to put to fine a point to it, but it is all about numbers. Play that 3v1 several times and, more often than not, the Russian's will have at least 1 T-34 survive. Especially since both sides had the same crew quality.
A recent turn in a pbem I had is more typical with better numbers. 3 Nashorns hit hull down positions on a ridge with 10 T-34's between 800 and 1000m. Thanks to borg spotting all the T-34's open up immediately. By the end of the turn each Nashorn had killed at least 1 T-34 and was, itself, a burning pyre.
Sometimes, you're the windshield, sometimes, you're the bug. Keep at it.