score:11
As you pointed out, your basic premise is wrong. There is nothing "h*m*genous" about the Egyptians. Just for starters, centuries of Arab conquest changed that. Even in ancient times the Egyptians had different ethnic groups living in different parts of the country, and the ethnicity of the royal family and nobility was considered different altogether.
In modern Egypt, both Muslim and Christian Egyptians are descendants of the ancient Egyptians, but carry different admixtures which results in them being slightly ethnically different today. Speaking of Alexandria, it is worth noting that the Greeks ruled Egypt for many centuries and there was a huge diaspora to Egypt out of Judea in Roman times.
In Medieval times the Byzantine Greeks and the Turks both occupied and ruled Egypt, creating their own sub cultures and ethnic groups.
So, whoever told you that the Egyptians are "h*m*genous" or somehow descended from the pharoahs or whatever, has no idea what they they are talking about.