Because it was NOT a myth on the unit level. Say Division or smaller. Either that or studies made during the war were attempts to cover up allied bungling of small unit tactics and training. If German troops were ( to pick a number out of a Hat) 1.3 times more effective than allied army "A" troops it doesn't matter to the out come of the war if the German leadership bungles things so badly that they have to fight 2-3-4 times their numbers. Their "edge" gets swamped.
Im not arguing that at a tactical or operational level the Germans did not excel. Go back and read my post carefully. They had tremendous advantages....and still lost, In the end they were out numbered, and badly so, but that just didnt happen, it arose because of the attrocious Nazi leadership.
At the beginning of the war the Germans commanded the second most powerful economy in the world, and the most powerful was neutral and disorganised. They were several orders of magnitude stronger than both the British and the Russians. And at the beginning the Russians were on their side. The French economic power was negligible....about 2% of world GDP compared to over 15% for the Germans. Britain was about 10%, but was falling rapidly.
Strategically the germans were short of manpower, that is, over the long haul. But at the beginning of the war they had vast reserves of trained manpower, as did the Italians. The British had fairly good reserves of manpower, but it was largely untrained. And it took about 18 months for them to rectify that. When the Americans came ito the war, it took them even longer to train their vast reserves of manpower, and it remained a problem for both armies to keep up even with modest casualty rates even at the end of the war.
The Germans used a combination of motorization, tactics and numbers to win their early victories. at Sedan, for example, they were able to hit the poorly trained and equipped French with well trained and well led troops, that because of their motorization were able to achieve decisive concent5rations at the decisive point and moment.
This was rfepeated in the following year in Russia where the purges made the Soviets even more vulnerable.
These are by no means the only advantages enjoyed by the germans. But to illustrate my point, in one or another, the German leadeship, including the army heads, squandered all these advantages, and not because they were being pressured or outnumberd. They lost these advantages because of very poor management.
In the case of motorization, the failure to rationalise the MT park by overhauling their support industries, meant they steadily lost their mobility advantages (more rapidly than it should have, because the plethora of types made maintenance and spares a nightmare for them) . This particualarly affected the line Infantry formations. In 1941, the average German Infantry Div had over 6500 Draft animals (in part coutesy of the British Army, who had sold their horses to the heer before the war), and nearly 1000 other MT vehicles attached. By 1943, the average numbers of Draft animals were down to about 3000, and the average number of MT vehicles to about 300. On the eastern front in particular, the Germans were no longer capable of even fighting a defensive mobile war on a front wide basis . they were able to strip out sections of the front so that other bits could get mobile, but once the initiative was lost, after Kursk, they could not retreat or advance without suffering huge losses due to a lack of mobility. this was a totally avoidable crisis, and arose because of stupidity more than anything.
In terms of manpower, the germans retained the largeest army of any nation on earth until 1943. That inludes the Soviets, if one does not include the hasty conscripts dragged off the street, handed a rifle (or often, not even a rifle) and sent to the front. If you want to argue these drafts were "soldiers", then the Soviets had the largest army from June 1941. But according to Dupuy, at this time, the Soviets were qualitatively outgunned to the tune of being only about 10% effective per man as the germans. By the middle of 1943, Dupuy estimates this advantage had shrunk to 2.31 times. But what was known by the germans was that the Russians would have tremendous resilience in terms of their manpower reserves and their ability to trade space for time. They should have made massive adjustments to their replacement army, increasing its ability to train and process men when they were needed. They failed to do anything, and as a result, by 1942,, the German Army in the East was nearly 1 million billets short, and by 1943 the frontline formations were down to about 40% authorised strengths. despite this, they insisted on continuing their offensives, moreover it was a situation that could have been handled far better but was not. No other army made that mistake, including the Soviets. everyone else had the ability to check how much cloth was in the cupboard before embarking on major offensives. Yet, somehow, the Germans were the best military planners on earth. you think!!!!!u
And there is only so much that combat units can do. They are dependent on supply and the German army units almost always operating on a shoestring ( a broken, tied together one at that) after the first few campaigns.
Logistics is still a part of military planning, and in this the germans failed miserably. it neednt have been so. They entered the war with the largest reserves of trained manpower, one of the largest armiues, the largest wartime ecomomy (the US was not at war), motivated leadership, a good plan, and yet they still failed. And it wasnt all Hitlers fault either