The point isn’t so much the myth as the logistics that got lost in translation. Sparta had a handful of hoplite infantry—maybe a thousand or two—armed in full hoplite gear and a few chariots or light transport units, all relying on the local supply lines. The Persians, by contrast, had a vast army, possibly fifty to sixty thousand, and they could bring their own food, fodder, and equipment over the mountains in convoys that the Greeks simply couldn’t match. So the “failure” is essentially a mismatch in supply capacity and mobility. The Greeks had to keep their arms and armor, but their ability to resupply was limited to the small local farms and the river. When the Persian army arrived, they had a steady flow of provisions from across the empire, so their supply chain remained intact while the Greeks ran out of food and ammunition before the battle even began. It’s a textbook example of how strategic logistics can make or break a campaign.