I think the issue with the Avari, and even the true meaning of the term
Eldar, depends upon which citation one employs.
Not unlike the issue of Eldarin height, although I already know what I'm going to get if I make the seemingly impossible claim that
maybe not
every 'late' description Tolkien wrote about Eldarin height was meant to be fused into one concept. Ahem.
It's once again sifting among [mostly] draft texts, with certain ideas arguably revised, others made uncertain by a 'lack' of mention perhaps, still others written
years after something else, made all somewhat nice and tidy by Christopher Tolkien, for us, but who knows what Tolkien had in front of him when he was creating a 'new' text years after he had written something related...
... I put author-published description in a strong postion. We are looking for a measure of certainty it seems, at least often enough [I don't want to be certain of all things, myself, and like plenty of the misty elements], and despite even Tolkien's penchant for change, which arose even with respect to already published text [for example publishing that Galadriel's father was named Finrod, then (second edition) changing it to Finarfin], author-published is as 'certain' as we can get in my opinion... with even Tolkien illustrating that he is revising a different animal, if so.
Anyway there is text in
Of Dwarves And Men which suggests that the idea of Avari in Beleriand was rejected; and late text in which the Tawarwaith, or Silvan Elves, of Mirkwood are simply noted as Telerin Elves in origin, hardly to be distinguished from Avari.
But that seems to distinguish them to the reader! And it's later description than
Quendi and Eldar, and again, the Avari of Beleriand seem abandoned according to
Of Dwarves And Men... sooo, what of Avari in the Anduin Vale however? Abandoned idea or back to
Quendi And Eldar for that much? In any case the Avari are not mentioned outside of the remark I referred to, so read it as is, and arguably there's no real reason to think any Avari, Tatyarin or Nelyarin, had mixed in by Frodo's day.
Or is there? Not that I recall. Again if we toss in a text made years before, then we have the concept rather certainly. But that's a different matter... again keeping in mind that
that text has the Avari in Beleriand!
And then there's the tantalizing notion [published by Tolkien] that the Silvan Elves of Lorien sail Over Sea. Hmm, would Avari sail? Could they sail? Was it only the Silvan Elves of Telerin origin that sailed, although that is never stated in the published account itself... it's just implied that the Silvan Elves in general could sail Over Sea if desired.
Mix and match. Hey it's not like I don't do it too, or think it's wrongheaded in every case. Tolkien, after all, need not be confined to tell his full 'tale', or explain every matter fully, within each and every text, for the other side of the coin here.
I'm just sayin'.... maybe a little less certainty with respect to some of these height and strength issues?
Or nah. What fun is that
And I won't even go into the definition of
Eldar... although one of these passages is Tolkien-published. Huzzah.