Erm....why so sure it's 76mm and not 85? Is the 11mm difference so obvious? Not that I take the 76mm ammo incapable of doing that damage, I'm just intrigued how you arrived at that conclusion.
I always thought this was a staged photo and it shows the result of a field test on a captured Tiger.
Back to the topic: the combat ineffectiveness of the Russian AFVs in the game is evident. (In that particular situation. Many considers the Russian side stronger in the overall game).
The penetration model (the formulas which use the historical penetration values) is close to reality, maybe on the pro-German side, but not much. The damage model however is a bit simple for nonpenetrating hits (though still more complex than in other wargames). Engine malfunctions, armor weakening, cumulative structural damage, spalling played a major role in actual combat than in the game, and this also skews the balance.