Slaying of Elves by Elves

[Eomer of the Rohirrim]

Apologies if this has been discussed before. I couldn't find it with that dratted search engine. Please, Barrow-Wight, oh please won't you get a better one?

Anyway, the Silmarillion lists the 3 incidents of the slaying of Elves by Elves.
Being, the Kinslaying at Alqualonde, the battle in which Dior was killed, and the battle where Elwing escaped by jumping into the Sea.

What about Aredhel by Eol? Or Eol by the Elves of Gondolin.

And wouldn't it be likely that the guards slain by Maedhros and Maglor were Elves too?

[Selmo]

The three incidents the Silmarrillion calls kin-slaying were large-scale battles in which many elves died on both sides.

Maybe they wern't so worried when only one or two elves were killed.

[Túroch]

Also remember that Eol was not really Sindarin or Noldorian, he was by all intents and purposes as dark elf loved by nobody (and for good reason). His actions were made by one elf and not any army. PLus the exection of Eol by the Elves of Gondolin was justicee not murder.