One of the things Unity of Command does well, in my opinion, is model the differences between the two (in general terms) opposing sides in terms of their particular strengths and weaknesses, without an abundance of abstraction or detail.
For example: the Soviet infantry formations are not really all that good by themselves. If you give them artillery, or a tank specialist step however, they become more useful and can attack their German counterparts. You should generally avoid strong Axis mobile units as the Soviets, also historical, but you can crush weaker ones with numbers.
This also means the pace of the advance is generally a bit different between the Axis and the Soviets. The Axis can make rapid advances with their mobile units, with the infantry cleaning up the flanks. The Soviets really need to get going like a steamroller, before their mobile units can break out by themselves.
For the Axis, creating the conditions for a successful breakthrough can generally be done in one turn. For the Soviets, it's often a multiple turn process.
WitE Alpha tester
Panzer Corps Beta tester
Unity of Command scenario designer