It becomes even hairier when most people's only "historical" exposure to the character is in fact from fanfic! For example, I once met someone who insisted Richard III of England was a much better king (and Henry VII a correspondingly greater bastard) than is popular opinion... but most people haven't studied the era, they just take Will Shakespeare's word for it.

This is the quote you posted. You seem to be saying that this person got his impression from reading shakespeare, and that most people haven't study the era. I'm sorry, but to me it reads as if you're saying that Shakespeare isn't a credible source. That's how it reads to me.