Of course the URL has to appeal to the wannabe driving his lifted pickup truck, it has the word warrior in it. You get all these meatheads with delusions of being some sort of Spartan badass because they took 300 as a documentary.
The Persian Empire had basically abolished slavery. Xerxes is noted in particular for being a far kinder conquerer than the Greeks were proven time and again.
Whatever you can say about the fledgling democracy of the slave state Athens, it would be destroyed by Sparta eventually.
All slave states deserve to be destroyed!
But in that war at least, yes. How much time do you spend judging Alexander for his conquests though? It's just what those assholes did to each other in the Iron age.
Personally I'll root for the imperialist assholes who don't have slaves.