The main problem with the Panther and the Tiger is that they were highly engineered armoured vehicles which other have said were prone to breakdown, whereas the the T34 was rough ready and could be assembled quickly and with the 76mm gun very good. Produced in amazing numbers even driven out of the factory at the Battle of Stalingrad and straight into combat. Remember how many Warsaw Pact armoured vehicles if the Russians ever wanted a holiday in France had, you may have run out of anti-tank assets including missiles before they ran out of tanks.
In the end it does sometimes come down the quantity against quality argument, put enough armour into a small area, even though inferior you may win the battle. but sometimes with superior skills and tactics including the battlefield a small number of armoured vehicles may have a disproportionate effect on the outcome, for instance the Battle of Villars Bocage in Normandy.