The Marble Phalanx
The hoplites here are Dara Happans from the Marble Phalanx, one of the famed Stonewall Phalanxes. They are heavy infantry that fight in phalanxes, and who have the Polestar as their patron god. They are not effective as skirmishers, and it their use here as “tax-collectors” (in this case as organized plunderers) is a possible sign of the military incompetence of Governor-General Euglyptus Assiday (popularly called “the Fat”). Several years after this incident of the Starfire Ridge, several Sartarite tribes rebelled and temporarily overthrew the Lunar occupation in what is called Starbrow’s Rebellion.
Argrath here is surrounded by the “Hero Light” and is channelling the power of Orlanth, his personal god, to strike down the Lunar soldiers. That Argrath can perform such a feat without being a full-time devotee of the god is a sign of his magical potency (which was also demonstrated by the depth of his initiation quest).
Are those Lunars? They look like Yelmalions.