It sounds as if this clan has been at the center of many a problem. Such things do not happen overnight.

[ hello, beleth. thranduil sounds very tired. by the sound- well, the lack of sound, he's not in the library. likely his rooms. ]

I do not think the Men will bother to separate clan from clan. Any group wandering in that area is at risk, any in Orlais like to be stumbled upon and hurt for vengeance, which will only heighten the chance that another clan will sour against Men so violently.

[ he stops speaking. he's coming to realize that the sort of change he and galadriel hope to foster cannot be done slowly, a gentle understanding built over generations. this world is built on blood and pain and suffering-- scars in the veil from death and loss and still that is not enough to convince those who maim and slaughter than it might, perhaps, be a good idea to stop. even the darkspawn are not enough to make them unify. ]

There is no way this... event can be read that could not be twisted to justify further death.