The Kentauroi tribes are one of several cross species hybrid creatures including satyrs, sileni, and the bull-horned centaurs of Cyprus. The centaurs (and possibly all the hybrids) were the creation of two unusual gods. Nephele was an intelligence distributed through a cloud of nanites that (perhaps as a joke on the part of Zeus) typically coalesced into a semblance of Hera. Nephele's co-researcher and transport was an intelligent saucercraft called Ixion. Nephele provided gentle persuasion, while Ixion's weapons provded force when necessary.
The centaurs were loosely based on the design of Chiron, a forgotten creation of Kronos, and an immortal in his own right. Nephele and Ixion's design for a hominid-equine cross didn't have Chiron's intelligence or immortality. An initial breeding population was released in the area of Mount Pelion. Once this group became established, some were relocated to the western Peloponesse.
The centaur tribes are considered savages by the Greeks. They have not mastered metallurgy or agriculture. They trade with more advanced cultures for metal weapons and alcohol--if anyone is foolish or greedy enough to give it to them.
Mutant Future Centaurs would be the same as their Labyrinth Lord counterparts, except of course they have the mutation aberrant form. Cyprian Centaurs with horns are able to substitute their one weapon attack or their two hooves for a head butt doing 1d6 damage.