Not that you demanded it, but here's the three ringwielders in all their stereotypical glory:
https://ringsdb.com/decklist/view/10955/a-stereotypical-three-rings-deck-1.0
Just missing the cut for allies was a lone copy of Leaflock. Why? A couple of the decks were ent-focused and reached out to Cirith Gurat to get the most recent ent ally, and with so few of the 30 decks using cards that recent (only half used cards released after Flight of the Stormcaller) it did well on a percentage basis.
Aside from the rings (required), the only 100% usage was another recent card -- all three decks that took cards from Crossings of Poros or later used Magic Ring. Appropriate! Just one of the decks left out Wizard's Pipe, and just one left out Gandalf's Staff -- they weren't the same deck.
In events Test of Will (21 decks) and Elrond's Counsel (25 decks) were the most popular picks. Free Peoples was included in 2 of 7 possible decks and just missed the event cut, with the thematic White Council (6 decks) being next in order.
Gildor and Glorfindel were the most popular allies with 21 decks each, but since only 24 decks used Glorfindel's pack or later, he was the most popular by percentage, with Jubyar (8/11) in second place. Treebeard made 20 decks, and Arwen, Bilbo, and Beorn made 18.
Here's the allies included in only one of 30 possible decks: Brok Ironfist, Galadhrim Minstrel, Mithlond Seawatcher, Warden of the Havens, Elven Jeweler, Galadhrim Healer, Ethir Swordsman, Errand-rider, Anborn, Descendant of Thorondor, Winged Guardian, Dori, Ered Nimrais Prospector, Lorien Guide, Denethor, Eothain, Gamling, Hama, Guardian of Rivendell, Harbor Master, Grimbold, Warden of Ammuninas, Daughter of Nimrodel, Riddermark's Best. Now build a Vilya deck with just those allies! I think Winged Guardian was in the only deck that included Song of Battle, for obvious reasons.
Only one deck dipped into the current cycle, so their picks weren't eligible for inclusion by my methods. It added Necklace of Gurion, Woodman's Clearing, and Arkenstone.