I wish I had a great artistic breakthrough here, but it's really straightforward. I just popped some extra heads I had from my Gripping Beast Arab spearmen and archers on the Mongol bodies and I was pretty much there. While I'm sure a cultural anthropologist would disagree, from a historical mini gaming perspective there don't seem to be any major costume features that separate Saracens from Mongols from the neck down. At least, as I painted these dudes, I completely forgot they were ever supposed to be Mongols,
Yes, I realize that Gripping Beast does plastic Arab cavalry at about the same price point. Fireforge's Mongols appealed to me more. You get more scimitars with them. 
I dig these guys with their full head wraps. Note that I made one of these dudes leaning as far back as possible to take a Parthian shot to the rear.
I didn't realize while I was assembling them that most modelers place a horse archer's quiver at his hip rather than on his back. That's too bad, because I like to model the pose of reaching back over one's shoulder to draw the next arrow. Can anybody speak to the historicality of quiver on back vs quiver on hip?
Had to let this adorable figure get in on this post. He's a stray Castaway Arts infantryman. If you are an ancients/medieval 28mm wargamer and you don't know Castaway Arts you should really give them a look. They're Australian, but it's cheaper and faster to order stuff from down undah than you'd think... no worse than ordering from England (I'm located in Virginia).