I was a US army border guard defending the Fulda Gap in 1976. Our equipment was in sorry repair and lacking spare parts and I was absolutely convinced that if the Sovs and their WP "allies" came across that nothing would stop them. During Vietnam all the $ went that way, afterwards USAREUR was in a sorry state. Then on another forum I had a chat with a guy that was in the East German army, and he said much the same thing about the Sov army. Problem was that the Sovs had such a numerical advantage in everything that their junk would likely defeat our junk. Years later Reagan passed a spare parts bill that got the equipment repaired and then got them the Abrams.
Before the Abrams we had the M60A2 which was too tall. The firing systems were supposedly not superior to the Sovs, so again in '76 and '77 we would get crushed. I was outa there in '77 when my 2 year enlistment was up. After Vietnam they had those. My main reason for getting out is that I considered we could not win a conventional war with the Sovs and really it absolutely must have gone nuclear, so why was I there? Plus the European NATO members didn't commit enough for their own defense so screw em. The hypothesis of this thread concerning a conventional war with the Sovs, at least when I was there, is very far fetched. For one thing the US put tactical nuclear missiles into the hands of the West Germans, well the US kinda shared them, but the Germans could have launched supposedly. This was to scare the Sovs not to attack when NATO was so weak according to my understanding, and perhaps it contributed to the fact that the Sovs never invaded.
I don't recall when the Abrams was widely distributed and the Leopard as well, but that was when even a Sov attack would likely have failed. F-16 too...
If you're building a game, don't forget the Reforger Divisions, heavy divisions, which flew in from the US and met up with prepositioned equipment.