Tempted to say blackbeard but I would imagine no one would care what he had to say on the matter, what with the being a horrible romanticized bandit and all.
Next mention goes to Jason. While I would argue Jason in FGO really is just kind of a look at how he would be perceived by modern standards and isn’t really super far off the mark. In his day he would have been considered a paragon of heroism.
I am sure several gender flipped servants would probably be less then happy. Particularly ones from societies were women are treated like property or puritanical ones where that would offend their religious senses.
Nero while recent historical evidence suggests while a terrible leader they were not the monster that most people learned about in history class, fairly sure he wouldn’t be able to take the joke.