History is never that told by the winners... Sicilians stayed 750 years with Vikings and only 100 with Arabs among whose only those who accepted Islam Faith were admitted on free tax exemption thus you can think that not so many were converted or forced to. The only problem of Viking Domination has been their excessive allowing rules for the stranger communities just like Arabs who were a minority but a persistent minority in the island of the Sandars, the Warriors of the Mediterranean long before the Pyramids in Egypt were even built.