Thousands of years and hundreds of generations have passed, and intermixtures of genetic lineages of Abu Sufyan and a 'Roman' / Byzantine / Westerner are very likely and common. In fact, the lineages of the latter of the 12 Imams after Imam Zainul Abidin (as) also had mixtures with noble (in the spiritual sense) African, Persian and Roman lineages. There was a finding some time back that the British Royal Family also had a tiny bit of Prophetic lineage (but no influence on their spiritual level).