Nothing wrong with your install.

The Sicilians used Muslim units often in a mercenary capacity, especially Saracen Archers, Spearmen and Horse Archers. Saracen to christians was also synonamous with Arabs.
Within the confines of the unit limit, which is reached with MedMod, the choices make perfect sense.

Futuwwas aren't actually muslim fanatics either. Futuwwa is roughly the Muslim equivalent of Chivalry and is rather a code of honour and on the peaceful path of life,

Futuwwa also signifies that one makes altruism and helping others one’s second nature and does no one any harm. It is an important, indispensable dimension of good conduct and a significant aspect of humanity.

A serious misnomer for a unit if there ever was one...

The only questionable one would be Murabitin Infantry as murabitin actually means inhabits a Ribat, so they are unlikely to have shopped out to christians but once again the unit limit is maxed and this was a playability and balance choice.