Iirc, it was legolas and 2 other elves that joined after the battle (elronds sons)

The other archers were humans

No, Legolas was the only elf at the Battle of Helm’s Deep.
Thats what is said, the other two joined AFTER the battle

True, though your comment was a bit cryptic.

I feel we really missed out, by getting Lorien elves instead of Dunedain rangers. Ofc they wouldn’t have been in such a prominent battle, like Helms Deep.

Though, actually they could have been placed quite well. I always disliked the army of the dead fighting at the Pelenor fields, in the movies, since it invalidates all the struggle of Minas Tirtith’ soldiers and Rohan‘s riders.

It’s way Vetter in the books