LMAO, wouldnt those odds be more like 6 to 30,000? Interesting you chose Halo, there's the Spartan-II cyborg (or whatever it is XD) and the Spartans at Thermopylae.
Oh and bernstein, if the Greeks used half-circle or circle formations with their hoplite soldiers i dont think they would have been very effective...
A reason why the Phalanx was in a tight box formation was because the troops in the back could deflect arrows, javelins, and the like with their pike/spear, since their pike/spear was at about a 45 degree angle. Also, the soldiers in the back usually push the troops in the front, and they are also there as reserves, but i mean whats the chances that a soldier in the front of a phalanx would die.
Also, to create a circle formation with spearmen would be very difficult to accomplish... maybe the Spartans could have had the training for that... wait how would they know which way to march in a circle formation? lol
If there was a battle with this configuration for a phalanx, i believe the hoplites were probably just confused.