Rian, Morwen, and their kids are all also members of the House of Beor, which could point to something Berenish or Tinuviesque; the issue with that is that there are 3 entries for which no Beorians have been suggested, and
Nerwen says that 6 of the names have been correctly guessed.
"Like-named" could indicate being named after someone. Actually my first thought was that all eight people literally 'share... a name', but the only way to pull that off would be to look at the [something]finwes, and we haven't guessed six of them yet.
hS