I would say Saracens will recieve the Indians treatment and get split eventually, but God knows how many DLCs will take to get there
Slavs might as well be renamed into Rus and you’re good to go
About the Turks I’m not sure. The wiki says Turks are meant to represent the Oghuz Turk originated empires (mainly Seljuks and Ottomans), this is, the most prominent Turkey based empires of the Middle Ages. They don’t represent something so broad like all Turkic people or anything, so a division may not be such a great need. Realistically you cant make a civ for every empire that existed, but you also want to cover as much as possible, so having a civ to represent a few different nations is not the big deal.