[Marcello]

"Funny thing is that nobody didn´t start a war. If Red Army had such huge advantages, it´s kind of interesting that they didn´t even try to pressure the West more politically or something like that."

I could ask a very similar question.Why didn't the US nuke the USSR in the late 50's-beginning of the 60's, when they enjoyed overwhelming nuclear advantage? Why didn't they even try to pressure the USSR more?
Which brings us to the answer to your question: nukes make people a bit more cautious.

"And doesn´t the game represent them as quite potent combat vehicles, considering the debate going on about their true quality?"

There is some fudge factor inherent to how ERA is handled the game.The T-64/T-72/T-80 have also peculiar armor schemes that is difficult to accurately represent.