No, obviously the Persians in the movie are fantastical and everyone recognizes that. The point is that Persians, enslaved to their kings, come to take away liberty from others. And on the other side, the Spartan force is voluntary, there was no compulsion by death, merely men and their conviction in the rightness of their sacrifice -- "tell Spartans we died here according to their laws", etc. On the one hand there's the Persian King, a megalomaniac who throws fetters into the Hellespont, to tell the river that he conquered it; on the other hand there are the Spartans with the first free constitution in history. Not that everyone was free in it, but the first people were free in it.