How can real people be called Dingus and Dinko? I hope they're twins ... speaking of which, not technically strange names in and of themselves but I did once know a pair of twin boys called David and Dave. If you ever shortened David's name to Dave he would look very confused and say 'that's my brother'.
As other ancestors have been named, I do have one that rejoiced in the name of 'Gilbertus Haddock' - I am descended from many Haddocks (and one Chadocke, who I think was a Haddock pretending) as they did have a tendency to marry their cousins.
However Gilbertus looked possible sensible when I found an ancestor whose name was 'Flarswort' ... you can't just go around calling people Flarswort - that's not a name it's not OK!