Amen Earl!
Between '39 and '41 I would accept full strength German units with some lower strength salt and peppered in. After that its problematical for any full strength. The Germans were feeling the man power pinch by then!
As for Tigers and Panthers lets see and I'm guessing here; ~5000 Panthers built and ~1700 Tigers built versus 50,000 Sherman's and 55,000 T34's. OK do the math a better than 11-1 for the Allies in advantage at least!
Another problem I have is in stock scenarios with greater than 11 visibility there should be 10 to 20 airstrikes for the Allies especially in '44. Remember the Luftwaffe was trying to guard Germany and not the Wehrmacht.
Finally take the total amount of German engineers in a scenario divide by 3 or 4 and round fractions up and that should be your German combat engineers in the scenario. Combat Engineers were very specialized and most of the time were used in repair of the infrastructure so divisional transport could get up to battle.
Ivan the Big