Quoting JMA:
If only the world could get over the Nazi connotations and also find a way to overcome the language challenge for english speakers to access German military writing then military scholars will find a new 'world' of military education open up for them. Anyone got a spare few million to start a translation project?
I thought there was a considerable effort at translating German documents, during the war and on a much larger scale after 1945? Plus a whole series of oral history interviews, a few of which became books later.

I would be surprised if training material was excluded.

Perhaps all the documents are too old, not indexed on Google and in filing cabinets in long forgotten places?