Why did greece win the third persian war?
I assume you mean Alexander’s invasion of the Persian Empire well led, professional troops with a skilled commander- against a huge, untrained, not motivated army led by a committee of politicians under the “command” of an incompetent coward Gaugamela is the best example- 3/4 of the Persian army ran away when they saw their King run away the 1/4 which remained was enough to hold the Greeks and take and destroy their camp- only to be forced to retreat when they realised their King had run away
