Do they model real units/tanks from the war like with the aircraft?
I know my PzKw III ausf.L has a elefant on it but no numbers, and my PzKw IV ausf D has marking for Panzer Regt. 31 and 5th Panzer Marking, the yellow X, which is a varient marking(don't know the dates used) and not the stand divison 1940 marking.
question about 21st Ground forces?
I dont think it is a priority, at least in the begining. They have always had unit markings, but numbers were not matched as far as I know. However in the 1:18 scale Ltd edition Wittman Tiger has come out etc. Also the new tigers has markings of the 505 HTB ?? So I think it is now going to be this way going forward. More accuracy!