I feel like OP's point was not full historical accuracy, more a greater historical feel and grasp of the period of engagement. Although balance will always dictate there being a few units that perform ahistorically(in terms of role, due to roster deficits) each of the armies should be represent the equipment available for them at the time, which we can roughly state as early 1945. Manpower and Production deficits are, of course, mostly ignored for balance reasons.
TL

R - CoH 2 should try to be a little more accurate composition and equipment wise while remaining mechanically the same.