I also don't buy Lehndorff's story that Fredersdorf stepped down out of jealousy over Glasow, seriously.

I think our Lehndorff made the same mistake many people do, to use their own emotional spectrum and likely reactions as a basis to draw conclusions from. Don't forget, as he admits in his annotation to his youthful entries which he made decades later, he was ragingly jealous of anyone Heinrich favoured as a young man. So he was likely to assume this was how Fredersdorf must have felt about someone like Glasow.