When synthesizing this list, I was looking at cards that are asymmetrical in their effect, hard to interact with, or have little ways to remove or stop them
Glacierwood Siege I suspect many players will play Glacierwood Siege to get more Crucible of Worlds action going on, but this card can be a strong mill option as well
However, the moment you start to add staples like Academy Manufactor, Bennie Bracks, and Clever Concealment, you start to move firmly toward Bracket 3
One of the big trends in MTG Finance over the last two years has been the uptick of price spikes due to financial buyouts of reserve list cards
Prosperity allows him to turn each mana into two more mana (draw X off the Prosperity and then pitch each card to the Bloom for 2 each)
I could imagine, if brackets are strongly and widely adopted, us talking about it as a potential Game Changer, but we are a long way off from that