Pretty nice strawman there. Germany was facing a France in 1939 that doctrinally fought like France in 1918. The USA was facing a Germany that was at the cutting edge of doctrines and did pretty well. Germany suffered more than 1 million casualties in 1944-1945 on the Western Front. The Allies in total suffered less than 750,000 casualties, the majority of soldiers being American, operating on foreign soil, away from US strategic depth with horribly complicated supply lines.
And of course, Germany had a highly educated and powerful officer corps from the start of the war. American military doctrine was in some ways inferior to France in 1939 and had a lot of catching up to do. By 1944, all major nations had adopted a lot of German blitzkrieg tactics.
My point is that Germany's early war performance is more to do with luck, timing, innovative tactics like using radios, and bad tactical assumptions on France's part instead of some inherent flaw in American military doctrine which had nothing to do with France. Remember, by 1944, the US was outperforming German armies on a casualty basis and also achieving their strategic objectives while Germany was losing.