Galadriel aided by Nenya... as powerful as Melian?

[Inderjit Sanghera]

But remember that it is also told that some of the Eldar that lived in Valinor, at least the greatest among the Eldar (Galadriel included) grew to be as powerful as a maia.

I think that that Finrod, wasn't as powerful as even the weakest of the Maia. It's a quote in one of the at three HoME's I think. Finrod is one of the most powerful of all the Eldar.

Three times Lorien had been assailed from Dol Guldur, but besides the valour of the Elven people of that land, the power that dwelt there was too great for any to overcome, unless Sauron had came there himself.

LoTR Appendix; Tale of years

I think maybe Iarhen misunderstood the quote.