I need at least one unit of such troops for a Lion Rampant 13th century Sicily project. I have the Gripping Beast 'Arab' Light Cavalry set, but the two torso variants contained therein in fact represent Turkish/Mameluke and Turcoman costume rather than that worn by Arabs. They'll find their way to the Holy Land at a later date. This is my proposed solution to the current lack of genuine plastic medieval Arab LC that should work not just for Sicily, but also for the Crusades and, with the right shields, for the Iberian Peninsula.
I also have a set of GB Arab heavy cavalry, and a box of Fireforge Turcopoles whose historical counterparts were, originally at least, composed of Syrian Arabs. I considered using the latter as is with appropriate heads, but the horses provided lack the tassels that adorned medieval Arab steeds and have a Christian short saddle blanket rather than the elongated Islamic type, and the riders' style of dress doesn't match that depicted in 'Armies of Feudal Europe' by Ian Heath: an ankle-length robe.
Interestingly, the horses in the Turcopole set are from Fireforge's Byzantine range and, along with the unarmoured horse models intended for use with the Turcopoles, the sprue includes all the parts needed to build them as fully barded.
Conveniently, it happens that both companies, whether coincidentally or by design, mould the riders' legs and torsos separately.
After inspecting the various sprues it occurred to me that by attaching unarmoured Turcopole torsos (half the torsos are sculpted wearing akhetons) to the GB HC legs I could achieve a pretty good representation of an Arab light cavalryman as per AoFE, and because I'd be using the GB horse models (the two brands aren't rider-compatible: GB horses are much wider than Fireforge horses, so only GB legs will fit GB horses, and the same applies to Fireforge) they'd also be riding accurately furnished medieval Islamic steeds.
Of course, this leaves half a box of GB Arab HC with no legs or horses, but fear not – the Fireforge spares left from the above mod will turn them into perfectly acceptable Syrian HC. 'Ah, but as you say above the horses lack tassels and have the wrong style of saddle blanket', I hear you murmur. This is where those apparently useless parts for full barding on the Turcopole/Byzantine horse sprue come in.
According to Ian Heath in 'Armies and Enemies of the Crusades', there's plenty of evidence that a substantial proportion of Arab cavalry rode fully barded horses. Putting the Syrian cavalry figures on barded horses at least disposes of the saddle blanket problem, thereby saving much conversion time, but it will still be necessary to add Green Stuff tassels.
One point to note is that, although the two brand's torsos match very well dimensionally, for some reason the GB lower bodies are recessed at the waist, while the Fireforge lower bodies are slightly wider than the rest of the torso at that point where a belt is sculpted on. This means that some filling will be required at the waist on the newly-created Arab/Berber LC; the Syrian HC should be fine as is.