"a re-telling of Ancient Greek legend (the Anabasis by Xenophon."

Indeed. While I've not read the Anabasis, I have read other pieces of classic Greek literature and there does seem to be something of the 'heroic' and 'epic' which is successfully communicated in The Warriors I feel - including in the slightly more surreal or fantasy elements of course. The end sequence where the sun rises on the beach is quite one of my most favourite ending sequences ever. Not for the implicit violence remaining, but for the opposite - the journey is over.