Hitler certainly favored party "old warriors," but there were exceptions. What he did consistently require, especially by the height of the war, was total obedience at the expense of all other personal qualities.

Though flawed in some ways, Speer's Inside the Third Reich makes a convincing case that the Nazi party was anything but a meritocracy. While we must be very skeptical of a former Nazi minister trying to defend his actions, most of his descriptions of Hitler's inner coterie ring true. Hitler simply rewarded those who supported him, and those elevated to power in this way had many opportunities to interfere in the complex and overlapping German bureaucracies. Martin Bormann is a perfect example. As Hitler's private secretary he had no actual governmental portfolio but controlled access to the Fuhrer and constantly interfered with the state's administration.

Another perfect example is Von Ribbentrop, who was a dilettante with no experience in diplomacy. He did have some strokes of luck, but on the whole his ministry was guided by bunk ideas and ridiculous ideology. He was only there to channel Hitler's wishes.

Goring was certainly very bad at this job. He was addicted to morphine during the height of the war and would usually just say whatever Hitler wanted to hear. I point to his famous insistence that the Luftwaffe could easily supply the 6th Army at Stalingrad, a claim most of the serious military leaders knew was an outright lie.

As for the army, you had old school Reichswehr dudes like Guderian, Halder and Rommel at the start. The Reichswehr had encouraged an accumulation of talent and knowledge during the 20's, when it was reduced to a rump by the Versailles restrictions. Small and over-funded, it could cherry pick the very best talent in the nation. Though the army started as an independent locus of power, these generals gradually lost power in the course of the war precisely because they often disagreed with Hitler's ridiculous schemes, though plenty of them went along with the madness more than they cared to admit after the war. By 1945, Keitel, Jodl and other non-entity yes-men held the reins.

This pattern was repeated elsewhere. Some old school technocrats were not original Nazis, for instance Hjalmar Schacht or von Neurath, but rather conservatives who had allied themselves to the Nazis. They were typically effective and were gradually replaced with yes-men during late rearmament and the war years.

On the other hand, you did have some bureaucrats like Speer who were somewhat effective until the end - he probably overstated the case for himself - but they were few in number, and the Nazis didn't exactly have a promising method of drawing on talent. Their whole ideology was anti-academic, to the point that several professors in the 1930's were complaining of a crippling lack of science and engineering talent matriculating through their schools. Speer was an architect who became Minister for Armaments, and he was one of the most effective ministers. That career path alone points to a seriously flawed system of talent selection and promotion.

The Nazis were genuinely great at one thing: propaganda. Credit where credit is due, Goebbels was a genius at mobilizing and brainwashing the masses.