I think it depends on what period you are interested in. From what I understand, as time progressed fashion/styles became more distinct due to different influences. For example, in the east, early on, Persian styles influenced the Muslim Arab, then the Turks. Whereas in Spain western Europeans had influence, then the North Africans and as Muslim power decreased in the Iberian peninsula the Caliphate became more conservative. So... if you were building an 11th-12th army from Granada you would probably stay away from those light cavalry torsos and heads with distinctive Turkish dress and be better off with Conquest Norman Knights with heads swaps or a little conversion; however, later on, Turkish cavalry started appearing as mercenaries in Spain. The infantry with face veil (tagelmust?) look distinctly North African to me but would appear anywhere Jihad takes them- whether it is the Iberian peninsula or Persia.