[Formendacil]

And what about Elrond in the First Age?

For the first 50-100 years of his life, Elrond lived in a society that was VERY dangerous for Eldar or Edain. And he wasn't even on the relatively safe Balar with Gil-galad and Cirdan, but rather he was with the mainland-bound Sons of Feanor.

Also, note that he and Elros were raised by Maglor. Maglor might have been the most pacifist of the Sons of Feanor, but do you honestly think that a three-times Kinslayer would allow his adopted sons to sit by idly while they fought for their very lives?

Also, in earlier versions, the son(s) of Earendil took part in the War of Wrath. As far as I know, this remained the case in the later conceptions.

Elrond might have been a pacifist come the War of the Last Alliance, although I would wait until after if I were to date his retirement, but it is plain that in earlier times he must have had to take up the sword.