T-34 was good but lack of the radio and commander copula in early versions makes it an easy target and not that effective even in bigger numbers.
The slope amour is certainly a good thing but I would not consider a flat amour so outdated in 1942. It allowed them to make better use of the space and slightly angled it was nearly as effective as if sloped.
Panther was the best tank in my opinion but it suffer from the extra weight a lot. I would choose it over the Konigstiger.
And I would rather choose M4A3E8 (Fury) for army in 1945 even though T-34 already had new turret and gun by that time.
Yeah Soviets made nearly 86 000 tanks and were given over 11 000 from UK and USA. Germans made nearly 25 000.
Half-tracks were crucial. But Soviets had problems to even get ordinary trucks so the USA send them some - both trucks and Half-tracks.