Leonidas’ performance as overall Greek commander at Thermopylai has been strongly criticized in recent years. For one, he did not pay enough attention to guarding the other ways across the mountains. The "fleeing" of the other greek contingents is now widely interpreted as a belated retreat in which Leonidas’ Spartans as the rearguard were pulled out too late and got trapped, while the traitor may be an invention to cover up Leonidas’ blunders. However, his performance certainly was a shining example in comparison to that of the Persians.
The usual numbers given for the Greek defenders are sketchy at best, too. Example: Every Spartan Hoplite was usually accompanied into battle by four to five Helots. Given the number of 300 Spartans would either mean that their actual number was around 1500 or that Sparta would have sent a contigent of 60 Hoplites only, which seems very few to accompany one of their kings.
Certainly the battle was turned into a propagandistic showcase to fire the Greek will of resistance. However, contrary to popular belief, at least up to this point there was no codex in Spartan history which forbade capitulation under such extreme circumstances.
Still, a battle map would be very boring indeed, as the pass was reported to be a mere 15 metres across at the narrowest part. That battle would not be much fun.
"I see no difference between war and terrorism. Terrorism is the war of the poor, and war is the terrorism of the rich."
Sir Peter Ustinov