"Never interrupt your enemy when he is making a mistake.” ― Napoleon.
From the Article in Armchair General "Hitler Takes Command!" by Nick Shepley:
"Shortly after the end of World War II, Lieutenant Gerneral Hasso von Manteuffel, one of Germany's most skilled field commander, was asked for his assessment of Nazi dictator Adolf Hitler's military competence. According to Donald Grey Brownlow's biography 'Panzer Baron', Manteuffel revealed 'Hitler had read a lot of military literature, and was also fond of listening to military lectures. In this way, coupled with his personal experience of [World War I] as an ordinary soldier, he had gained a very good knowledge of the lower level of warfare - - the properties of the different weapons, the effect of ground and weather; the mentality and morale of troops. He was particularly good in gauging how the troops felt. I found that I was hardly ever in disagreement with his view when discussing such matters. On the other hand, he had no idea of the higher strategical and tactical combinations. [Hitler] had a good grasp of how a single division moved and fought, but he did not understand how armies operated.'" [my emphasis in all cases]
There it is in the proverbial nutshell.
Hitler NOT knowledgeable in those elements of war that comprise strategy, grand strategy or the operational art. That latter the movement of units on a massive scale and basis to achieve strategic and grand strategic goals.
[Also Hitler during the Great War being evaluated and rated NOT BEING SUITABLE AS OFFICER MATERIAL. Mentally the man not so stable!]
Hitler having assumed command of the German military and in the position not only as political leader but then also acting the function of a generalissimo, commanding and directing with direct order the German armed forces, an incompetent man in control, MUCH TO THE ADVANTAGE OF THE ANTI-FASCIST COALITION FORCES. [the western allies and the Soviets]
[generalissimo as I understand the meaning of the word slightly in deviation with the dictionary definition. Generalissimo as one wielding both military and political control, actually in direction of the armed forces, moving units around on the battlefield at whatever echelon.]
Von Manteuffel that name literally translated means "Man-Devil". Hasso however seems to have a very distinguished war record without participation in "those things". OH, you know what I am talking about, "those things".