This is under-appreciated, very rarely talked about, and spot on!
I am personally guilty of being far too lenient and tolerant in overlooking "hard to work with". Bluntly, as an engineer, I enjoyed working with a few particular "brilliant assholes" (as their brilliance was often but their AH nature rarely directed at me) and so I tended to tolerate them too much when I transitioned into leadership roles. I don't know if that was biggest mistake as a leader, but it was for sure in the top five.
I am personally guilty of being far too lenient and tolerant in overlooking "hard to work with". Bluntly, as an engineer, I enjoyed working with a few particular "brilliant assholes" (as their brilliance was often but their AH nature rarely directed at me) and so I tended to tolerate them too much when I transitioned into leadership roles. I don't know if that was biggest mistake as a leader, but it was for sure in the top five.