So, here's my question: Is there any difference between the office corps of the United States Army as opposed to the Wehrmacht? Was the Prussian tradition of producing military leaders substantially different than the United States? And finally, what was it that made the German officer corps so effective?
I mostly agree with the summary of Fuchs. A few additional comments.

The tiny, 100,000 man Reichswehr under von Seeckt consisted almost entirely of officer material, most of whom initially had combat experience ( 7 year enlistments, if I recall correctly). The cap imposed by Versailles allowed von Seeckt to select the very cream of the crop. Many outstanding WWI officers tried to finagle Army slots, even on half pay or in the reserves and failed.

The Wehrmacht, based upon conscription, was not like the Reichswehr and the former was far more egalitarian than the old Imperial Army of the Kaiser ( the Waffen-SS even moreso). The middle class and lower middle-class made deep inroads into an officer corps whose higher reaches had previously been dominated by the junkers class. Politicization creeped in as well.

Hitler had far more operational control over the Wehrmacht in WWII than the Kaiser had over the Imperial Army in WWI. The Fuhrer had assumed the powers of the War Minister with the dismissals of von Blomberg and Fritsch, the chief of Staff and the creation of the Oberkommando der Wehrmacht under Keitl. Additionally, Hitler's sometime number #2 in the Nazi hierarchy, Goering was both Air minister and head of the Luftwaffe.

The U.S. military culture is -and has always been - unlike that which prevailed in the German military during the Kingdom of Prussia or during the Second and Third Reichs. The personal oath of loyalty taken to Hitler, for example, is inconceivable here as is the Imperial Army's position as a State within a State that existed under Wilhelm II. The American military is ultimately both more subordinate and less servile to the civil power in America than it's counterpart was in Germany during that period of time.