For reasons I am relatively okay with, the books really make no mention of which T-64s, T-72s, T-80s, BMPs, etc. If you are not familiar with Russian industrial naming conventions and background, it is super confusing. T-64As and Bs and BVs and T-72Ms, M2s, Ss, T-80A and B and U and UM and on and on and on. A T-72 can certainly be markedly superior to a T-64, and vice versa, depending on the versions encountered (which most laymen could never tell apart). Polish T-55s (AMs) would actually be superior to any Russian ones you would find (and look distinctly different), while Polish T-72s would be inferior to the Russian ones. It is a mess -- in part by design by the Soviets.
It would be nice to have this level of detail (along with support for things like reactive and composite armor and so on) -- but I am perfectly fine with that being withheld until supplemental/optional books can come out. I understand that FL is trying to cast a broader net initially, which is probably a good thing. The 1E/2E didn't make these distinctions either, really. In part because back then nobody actually knew all of this information, and instead we didn't up with weird guesses like the remote-turret T-90 and "AKR." But also because it's not primarily a game about tank combat.
However I will note that the 30mm autocannon was only on the BTR-80A variant, which was not super common. The base BTR-80 still had only a 14.5mm and was far more common. But again if this distinction is being made just for game reasons (BTR-80 = super scary! Earlier BTRs = only mostly very scary!) then I am fine with it.