Please forgive me if I'm ignorant, but I thought Ladros was the name of a place: the land in the northeastern part of Dorthonion where Boromir and his successors Bregor and Bregolas had their realm.
Anyway, for all it's worth, here is what I think is a link between Haldad and Boromir
Haldad -> Haleth -> Caranthir -> Angrod -> Boromir (or any other Lord of Ladros)
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