Which is exactly why you have a He-162: Cheap, non-critical, resources, dispersed production.
As Henning has pointed out, the problems associated with the introduction of yet another type to the LW inventory more than offset any savings in strategic materials that is might represent. Its a false economy that even the most elementary economic analysis will clearly demonstrate. I suggest you read Professor Overy's analysis on the management of the wartime economies as a starting point
And it's not like the Germans "started to generate shortages" they were forced upon them and they had to respond.
Ah, yes they did. To name just a few examples, pre-war, stocks of strategic materials were deliberately run down to dangerous levels, to enable more money to be spent in other areas, including non-military areas, like the beautification of Berlin. The Germans also made conscious decisions throughout the war to build "whole units" and not provide adequate spares for many major items of equipment. There were never enough spare engines, never enough gearboxes (and the like) for any items, including aircraft. The reason is, basically, to impress the Nazi leadership, Goring in particular, who were not interested in serviceability rates, as much as total units produced.
Which they did by basically focusing on a single piston fighter for further development and said jet fighter combo. As a matter of fact, of the He-162 a few hundred were available when the war ended. But not the fuel or the pilots to fly them.
Which does nothing to explain why there were at least two jet designs, and four prop designs that I know of, other than to create procurement madness and confusion
Regarding production: In 1944 fighter production was at its peak in Germany, besides the deteriorating situation and it increased until the collapse. All this thanks to standardization efforts and production optimization conducted by RLM and industry. And it showed: Take the Einheitstriebwerk for example: Effectively, it allowed Tank to build the Ta-152 with different engine than he had originally thought of. Without the need for any serious re-designs.
Yes, producing planes without spares, without fuel, and without pilots is an eminently sensible management of resources.......Even without too much allied interference the Germans managed to back themselves into a complete muddle, and sorry state of mismanagement. The Germans produced in excess of 40000 fighters in 1944, from memory, and just 8500 pilots to fly them. Even without allied interference with their petro chemical industry, there was an upper limit of about 5000 fighters that could be kept fueled and ready in 1944. In the Allied air forces, a P-51 had an average shelf life of 9 months (without combat attrition). So for the Germans, without combat attrition, if they have a similar shelf life, one could expect to maintain that force structure of 5000 with no more than 7000 fighters from the factories. On top of that, there is of course combat attrition, which for the Germans was running at about 1500 aircraft per month. That means to replace losses from combat, and maintain your maximum 5000 strong they would need another 15000 aircraft, roughly. All up, the Germans would have needed about 22000 aircraft to maintain their 5000 aircraft. They cant go past the 5000 mark, unless they find a way to increase pilot output, and fuel outputs. Neither of these were contemplated in the 1944 economic plans. So the result of this impressive production effort, was a whole bunch of useless airframes, sitting around airfields, waiting to be destroyed by the allies. Good management...yeah right.
That efforts were made to keep the lead over Allied jets for example goes without saying. But these were drafts, drawings and wind tunnel models. They didn't interfere with the existing production.
What about the efforts needed to set up the production lines. You make it sound that design resources are free and grow on trees for nothing. It cost six million dollars in the sixties for the Coca Cola company to design the ring pull opener, and they obviously saw that as a valuable piece of design work, because it is a fully patented system. if you statement was correct, people wouldn't worry about patents, because it costs nothing, according to you, to develop a new design. You have got to be kidding...... yourself, mostly
The Germans suffered mostly from direct interference by high ranking party members into procurement. The thing is, branch by branch procurement was different and as was interference. You make vast generalizations over the whole military and assume because of obvious and well know mistakes, flaws must be present in every branch and every procurement process. More specifically you applied your logic to the case of the late war fighter developments in question, which simply doesn't hold.
I would agree to this extent, the problem stemmed from the upper management echelons mostly, but their influence was such that all the good work done by the lesser managers at the middle and lower echelons was basically more than canceled out. The problem was at the top, but it was a massive, and overwhelming problem.
In terms of the late war errors, there were plenty of examples to demonstrate poor management, starting with Hitlers interference in the Me 262, moving to Goering's obsession with production numbers, at the expense of serviceability, moving to the proliferation of multiple types, which flies in the face of standardization principals. Then we can move onto the fact that the LW production program was not matched by any corresponding effort in fuel production, or to the numbers of pilots that might be needed,,,,,,,etc etc, The list goes on and on