If the US Army had met the Wehrmacht on the plains of say, Iowa, in 1942-43 the US Army would have suffered losses as bad if not worse than did the Red Army.
The Krauts simply had better equipment and better trained soldiers than the Americans.
It took a tremendous effort by the Red Army to stop the Germans at Stalingrad and Kursk.
I doubt that could ever have happened, ever. Germany did not have the industrial base to appear in Iowa. They could never, ever have done it.