The Muslim Egyptians are, to a large part, descended from the Arab invaders of the 7th Century.
Egyptians were not racism—skin color didn’t mean much to them—some pharaohs were white, some were black, but most were brown—hamic people. They should have cast Mexicans or south Americans. Egyptians were only interested in the Gods you worshipped. Cleopatra was a Greek—not one bit of Egyptian blood—but she spoke Egyptian (as well as nine other languages) dressed like an Egyptian, worshiped and ate like an Egyptian and was fully accepted as an Egyptian by her people (or most of them in any case).