Warlord Games previews a little bit of everything: Greek Phalanx, Hoplites, Psiloi, Slingers, Thessalian Cavalry, and Cretin Archers!
I told you it was a little of everything.
From the preview:
The hoplite phalanx of the Classical periods in Greece (approx. 750-350 BCE) was a formation in which the hoplites would line up in close order ranks. Shields locked together the first few ranks of soldiers would project their spears out over the first rank therefore presenting a shield wall and a mass of spear points to the enemy, making frontal assaults much more difficult. It also allowed a higher proportion of the soldiers to be actively engaged in combat at a given time (rather than just those in the front rank).