Actually, British-Israelites will claim that the original inhabitants of Egypt and upper Ethiopia were... Whites.
Now you're just debating archaeology and Genesis-interpretation.
However, in even addressing the question, you've already admitted that the British-Israelite/Christian-Identity folks are Racially-dividing the Body of Christ along Ethnic lines. As Winston Churchill reputedly said to the Lady of Ill Repute -- we've already established where you're coming from, now we're just arguing about Price (or in this case, "Which Ethnicity", which Racial Division... which Sundering of the Body of Christ do you prefer?).
Has any British Israelite ever posted a single post at Free Republic? I've never seen one. Yet you accuse those who believe that God has shown favor to the genetic descendants of Israel as the functional equivalent of White Power Replacement Theology Nazi's.
Frankly your point here, if it isn't to call everyone who disagrees with you a Nazi, is lost on me.
Do you find fault that God said "Jacob I have loved, but Esau I have hated?" Did not God curse the biological line of Esau?
What the heck is your point anyway?