Actually, the Russkis had better tanks than the Germans, such as the KV-12 and the T-34. The German tank pitted against the T-34 was the PKW-III with a 37mm or 50mm main gun. They had to change the role of the PKW-IV and equip it with a “long” 75mm to match it.
The PKW-V Panther was an attempt to copy the T-34 but Germans screwed it up by making it over complicated. The T-34-85 was probably the best tank of the war, in terms of numbers and capabilities.
What the Germans had was a DOCTRINE that used tanks in a more effective way than any of of their opponents, not to mention a radio transceiver in every tank (In Soviet tanks, only the platoon leader had a transceiver - the rest had receivers only, if they had radios...). They were able mass their firepower against the “decisive point” better than anyone else. The Russians eventually put an end to this with superior quantities of equipment. German fuel shortages did not help, either.
In January 1941 the Soviets had over 23,000 tanks.
By December they had slightly less than 6,000.
The Germans completely annihilated the Soviets during Barbarossa and it would take awhile to recover.
Thanks for the color! All interesting bits of history.