(To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there.) The value of X is determined only once, as Tromell's last ability resolves
Lets set aside the argument of what would be better in Legacy (spoiler: Mind Twist), despite the fact that Dark Ritual, Ancient Tomb, and City of Traitors are all legal
Black Lotus, The Moxen, and Ragavan are prime examples, as they provide an overwhelming resource or tempo advantage from the very first turn
But, unlike that, this is Command Zone eligible and has another trigger option hence it hits higher
Avatar Aang will be great in that very narrow archetype and useless outside of it
Maybe your opponents played their own Docksides Extortionists and racked up a few Treasure tokens that way, or they created their own through some other means