In RL - I have a cousin that named her child the same name as her older brother. And it's Micheal, so it's not even an uncommon name! So Micheal had an Uncle Micheal (by blood)
that is not uncommon
in my family we have 6 or 7 men named Jack on my father's side.
i gave up long long ago on worrying about inbreeding. they don't actually get the mutations and become deformed, so its not a big deal to me