Fuchs wrote,

The real test of competence for the German army was France, though. The U.S. military had no such test. Its major victories came to being with vastly superior, not about equal, resources.

For this reason I withhold final judgement of the U.S.ground forces' actual (relative) competence even for what's called conventional warfare. Their way of war and especially their love for gold plating and radio comms is dubious.

Bill; show me American ground troops fighting against well-armed opposition and we'll see whether this ability to destroy isn't overcompensated by an inability to survive in face of such an opposition.
I understand American army troops pride themselves in their supposedly unique quality at shattering formations, but this self-image appears to found almost entirely on fighting demoralised and 1970's monkey-model-equipped Iraqis.
If you're talking post Korea it is difficult, but I think an argument can be made that the US Army proved its ability to endure against a potentially superior force during the Battle of Ia Drang in 1965. Some may have some valid arguments to counter argue this.

It seems the fact of the matter is we simply haven't had a hard test in the past few decades, but I'm not sure what nation could test us in a conventional battle based on our current technological dominance? Obviously irregular warfare is a different animal altogether.