LOL!
I had a Duncan great-grandmother and married a Duncan, so I’ve got it bad! ;o]
Different lines, I’m sure.
Hey, if no one ever married a distant cousin, no one (even in the non-Moslem world) would ever *get* married. :’) I’ve never found any ancestral doubling, but I haven’t looked that hard, some lines only go back 12 or 14 generations.