The point is, you could opt to get a quick T-34/76 or wait a bit longer for better and more costly T-34/85. I think it's reasonable.
It'll probably have the previous problem with the former 34-76 placement in T3 though - why get a T-70 when you can save just a bit longer for a medium? (Worst medium in the game, but still a medium)
That's why I'm in with people saying to swap 34-85s and 34-76s around.