Back when you could combine beastmen, chaos warriors, and demons all in one happy family of chaos, I would run some chaos knights that were essentially heavily armored centaurs and resembled my beastmen. Back then I used the old Empire/Chaos horse with a gor torso to make the bulk of the centaur. It worked well, but now the new chaos horse is so much more detailed and much larger. So I'm going to return to that concept. The plan is to make a couple of different semi-blank torsos then cast them in resin to bulk out the army and add a bunch of details.
More on this project soon, and yes it'll be used in my Mutant Marauder WoC army.