Who would win? I think the battle would go something like this:

Achilles disarms Maximus at the start of the battle and dual weilds two swords, one in each hand and fight Leonidas, who has a Spear, and Maximus who draws a hidden second sword and they both fight Achilles. Achilles will grab a bow and arrows and start shooting at Leonidas and Maximus as they go head to head. Leonidas would back up and throw his spear at Maximus who would dodge it and Leonidas would get hit in the leg and then the torso by Achilles' bow, where he would then throw another spear at Achilles, nailing him right in the eye that would go through his skull penerating his brain. Maximus would then leap at Leonidas who would draw his Spatha and block Maximus' blows. Maximus would then duck under Leonidas' sheild and stab him in the heart but right before Leonidas dies he cuts Maximus' head off. So I say they kill each other.

What do you think?

I think you've pretty much nailed it on the head with the idea that they all kill each other. Assuming that Achilles isn't all immortal and junk in this, I'd say lil Maximus. Achilles, no because he seems over confident and Leonidas no because I could see him trying to be either overly tactical or being an all-out Spartan and going buck wild. Maximus on the other hand seems more level headed and flat out pissed off. I see him as having more anger and thus, the upper hand.

The one thing I'd disagree with you is I don't think anyone would have time to grab a bow and start firing. >.< It seems somewhat impractical in a heavy battle.

Still, I commend you for thinking up such a poll! Genius! -claps-

and...Who voted for Achilles? >.<