Or both, haha. The power of slooting shall save the land. Or, uh, cover it in spunk. I forget which.
Alas, no horsewang this run.
Actually, any shot of a centaur futa waifu at some point? I can't remember the name of the characters, but I recall seeing a bit of art with a reasonably gallant knight that functioned as the steed, but unfortunately had the habit of getting too turned on when her rider would be rubbing up on her from above.
And of course, she couldn't reach her big 'ol bits below. What's a handler to do, I wonder?
Oh, since you may have desert terrain to play with, they could be a nomadic tribe of some kind, so there would be a variety to pull from, gender and art wise.
Double oh, what if by the power of bullshit and pron, you either mutate or birth/sire a centaur of your own (probably a daughter, cause more adorable), and at some point you need to acclimate or teach them the basics from interacting or being accepted from mentioned nomadic tribe.
Or could just be an unfortunate orphen in Avadon needing a place and abandoned, cause people are the worst. That may be a better move.