Still missed that mark, famously. The "nobody was there how do you know" quote about Gladiator was specifically about the costumes, if I recall correctly.
Also, absolutely it claimed to depict the lives of historical figures. Marcus Aurelius and Commodus are people who lived. Important people, too. The entire movie is a bit of a alt-history take on the relatively anecdotal detail that Commodus was assassinated by a gladiator and that he used to fight in the arena himself.
Again, haven't seen Napoleon, but I'm gonna say I can see someone fictionalizing the life of a guy who has become shorthand for having an inflated ego and a whole bunch of jokey pop culture anecdotes. Is the bar meant to be different here? There was fictionalized apocrypha about Napoleon (and the rest of the Bonapartes, while we're at it) while they were alive and in charge. I think the statute of limitations is up on that one.