[thaumasiotes]

Well, the distinction mattered. But because the distinction mattered, the modern labels aren't really accurate.

Arabs were the highest-prestige ethnicity within their empire. But they were numerically insignificant. You have "Arabs" and "Copts" in Egypt today, but most of the "Arabs" are Copts whose ancestors decided they wanted more respect. Same thing is true farther west, where the "Arabs" are Berbers.

[taeric]

That isn't really addressing my question, I don't think? The assertion is that most of the Arab mixing into region came at the same time as the later invasions. Yes, they would have remained fewer in absolute numbers. But they weren't even there after the earlier raids.