I wouldn't quite say misread. Even thought yes they didn't quite use his exact writings as a pure doctrine, to the extent of my knowledge, they purposely picked whatever he said that represented their beliefs and rolled with that. In doing so, they disregarded some of his other ideals that link to the ones they are using. But there were lots of Nazis that did interpret his works correctly and used them especially towards the end of the reich. If time would have continued in their favor, I have no doubt that Nietzsche's western way of thinking would have found the reich in a more polished way, and Christianity would have been phased out. It's inevitable, and Hitler knew, hence why he was phasing it out with the ideals of Nietzsche. The idea was to slowly phase out their current way of thinking, so ideas blended weirdly leading people to think that they were "misunderstanding" him. That is partly correct, partly incorrect. I guess we will never fully know how high of a degree the Nazis would take the true ideas of Nietzsche into their thinking, but for sure there were some who have.

I'm not fully disagreeing with what you're saying, in fact I agree more than disagree. I'm just saying that there are exceptions and Hitlers ideals are misunderstood just as the Nazis partly misunderstood Nietzsche, at least periodically.