> "Hitler wanted X" and "Germany wanted X".
Well thats the point. Because even if todays borders are considered "untouchable" through international law, that was not so much the case in the beginning of the 20th century.
In fact re-drawing borders was exactly what seemed a completely legitimate way to "penalize" Germany/Austria for the Great War. So it is no wonder that Germans had no hesitations about the "land-grabbing" part of Hitler's policy - land grabbing was totally legit, ey?
Of course, putting those guys in charge of operation land-grab which had the most vile hatred of them all was on part of the German populace naive at best and complicit at worst. But then, what opposition to expect, if the Nazi-genocide's first victims were Germans, basically muting almost all opposition by emmigration or death.
Also, about the in retrospect outlandishness of the Germans for wanting to grab land from its neighbors - what did Germany's contemporaries do right after WW2?
Demanding to shift some borders: The USSR+UK at the expense of Germany and Poland with Germany loosing 30% of its territory. France incorporated itself the Saarland. The Netherlands wanted to increase itself by ~30% at the expense of Germany. Belgium had plans for annexation and even tiny Luxembourg saw fit some expansion.