Battle Specter Opines: Killin Persians

Sitting down at lunch today with my family, we got into a conversation about the Orcs from Middle Earth fighting the Orks from 40k. This led to a conversation about comparing apples to oranges, and I asked my wife, "Could we compare the capabilities of Zulus to US Marines?" "No," she replied. "Well, what about British soldiers to Zulus?" Again, she replied in the negative. To which I responded that the British had fought the Zulus and the Zulus had given a good account of themselves. then I posited the following: Could a platoon of Marines hold the pass at Thermopylae?

This got my son going. He's still got a lot to learn, but the question is now on my mind, and I have to at least hazard a guess (or rather, an educated guess) as to whether or not they could hold the pass. There are things I don't know- the terrain at the time of the real battle- but there are things I do know- like the max effective range of the M-16 and the M-249 as well as the M-203. My initial thoughts are that with what they have on them, no. They can't.

However... That's only because of ammo and weapons considerations (namely heat and fouling). If we grant the Marines a nearly limitless supply of ammo, and allow that they can effectively perform needed maintenance, and keep their weapons cool, things start to shift. Allow for the platoon to conduct their own missions to upset the battle in their favor, and I think, barring some serious fluke, the Jarheads of today hold the pass against the Persian force of 2000 years ago.

So I put this to you to discuss below: Can a platoon of Marines (3 squads of thirteen each broken into three teams with an M-16/203, two M-16's, and a 249 SAW per team) hold off the Persian army at Thermopylae? The following conditions have been met for the sake of the discussion. First, the Marines have what amounts to unlimited ammo (they need only to fill magazines and keep their weapons functioning). They have all necessary food and water on hand. They have one day to prepare their positions (but only with materials located at the pass). The Persians don't know yet what awaits them at the Hot Gates. The Marines have no outside support, but they do have access to supplementary weapons in the form of claymore mines, grenades of all types, and three AT-4s per squad (nine total), and one Corpsman per squad. The Marines aren't led by a butter bar- they have a competent LT and Platoon Sergeant.

I'm very interested to see what you have to say. Only caveat- you have to back up what you think. No simple answers here.