Furthermore note that the ratio of dwarf men to dwarf women is 3 to 1, and not all get married, so far from every dwarf ever gets to marry and have children, meaning this practice of selecting an heir that is not a son must happen all the time. Also Gotrek Starbreaker lived for a very long time because he was "too stubborn to die" as he had unfinished bussines with the elves, but he expired very shortly after the war. His wife, however, may already have been dead for centuries. The war ended more than 400 years after Snorri Halfhand died, after all.
I wasn't saying you disputed it, just pressing home the point of the gravity of elven lossesAs for Caledor and the Pheopnix Crown, I didn't dispute that, so what's your point?