what time period is the most even for US vs USSR?

[Imp]

Depends on your army & what you are likely to run into.
Georgia rather than using front line units probably used what was near by & cheap to maintain logistically,why pull T-90s & the like if its not warranted.
The West errs more on the side of big guns & saving lives possibly but even we only took the best ammo just in case & used the cheap stuff, well for the tanks anyway.
The airforce got to burn a nice hole in the economy.