Youre correct that there was a purge of military in Nazi Era Germany, but beyond that you kind of misunderstand the very collaborationist relationship that the nazis and the existing military industrial apparatus. I would really suggest reading The Economy and Class Structure of German Fascism by Alfred Sohn-Rethel for a little bit of a contextualization of why what you're saying is kinda surface level analysis. Separately I'd recommend Fascism and Social Revolution by R. Palme Dutt.