panzer4 G was superior to T-34. T-34 had no radios, you sat on a plank and drove around with a stick. German tanks were made of quality and comfort. Historic documentaries always likes to shit on germans and compares early models of panzer4 to T-34 but in coh2 we have the G model which was upgunned and could easily penetrate a T-34.
In coh2 we have different situation, when p4g from future 1944-45 meets t34 from 1941. As earlier was said, more correct compare p4g with t34-85, not 76. Germans not were fools, no one country don't produced tanks for comfort of their crew (tank not sportcar). They did their tanks used previous experience and works of engineers. As soviets did. And documentaries not throw shit on germans tanks. Main trouble with german tanks was their small quantity (thanks for non-war economic, soviets first started worked entirely on war) and troubles which grew from this fact (how many AT guns were in German divison in 1941 and 1944? and don't forget their increased weight) for World War you need quantity, not quality.
For p4G - why germans was must increased thickness of armor, while soviets remain the same? Because soviets has advantage with artillery and tanks (don't forget PTRS too). Why soviets not increase armor? Because it will increase weight and decrease reliability and speed of tank. Slow tank is dead tank. Slow, heavy armored tanks good for defense while fast tanks for offense (1941- fast, reliable Pz2 and 3 and slow, non-reliable t34-76 and kv-1).
In the same situation was KV-1, when germans bring on battlefield new AT guns and new panzers, all it armor became...useless. And were only 2 ways: increase armor, or decrease armor and increase speed. Was choosed 2-nd way (and then after KV-1 was ended to produce, was started to production new heavy - IS). Because, heavy armored, slow moved and breaking everytime tank the best target for artillery and other tanks.