It's a movie, designed to entertain. I do not think anyone is saying what is portrayed is the truth. What movie is the total truth anyway? "An Inconvenient Truth" is touted as the truth, but there is probably more fiction there than in "300."

Even history does not tell us the whole truth and nothing but the truth...because it was written by people. There is no such thing as a totally impartial and accurate person, who can be that at all times. All we really have are perceptions of truths, and like pretty much everything, YMMV.