Tazak is doing yeoman work of translating the contents of US Army Field Manual 100-2-3, Soviet Army Troops, Organization, and Equipment, into a data sheet for the game. That manual was published in June, 1991, so it gives you a feel for the time frame.
Bear in mind, this is a vast and tedious task and it really just gives you a template: this is what typical units have for equipment and how the units are structured. It's not an OOB in the sense of "here's what this Guards Tank Division had" on a given date.
That manual is a very handy reference for doing this task. I wish we had access to the equivalent Soviet info on NATO. It would be more comprehensive than what we have to work with NATO-wise. A good thing is there are a number of us here that served in those Armies and remember the force structures. Or, parts of them, anyways.