Hierachy of the Elvenkings

[Legolas]

whether Finarfin was 'King' or 'Lord' of the Valinorean Noldor, his position would be the same there.

Right, but that was entirely not the point. The point was that he was not a king, and thus in the event of a king's return to Aman, there would be no question as to who was in charge as originally posed by the intial post.

Also in response to the intial post, I don't think the sons of Feanor had anymore claim than Finarfin did (less, probably, after Feanor's eldest son passed it on to his other uncle). Those of Fingolfin's line would've had the claim over the title should it come to question...Fingon's line, and then Turgon's (Earendil/Elrond). If Feanor's sons were embodied once again, so too would Fingolfin, Fingon, Turgon, and Gil-galad, all of which actually were High King. I don't know that it would've been made a big deal of, though. Feanor's sons never seemed to care who was King or what they advised - they did their own thing, looking to fulfill the Oath.