If he did choose to downsize, it's likely that many of his cards would be among the most expensive Pokmon cards ever sold.
Matt Tabak writes in the official Innistrad: Midnight Hunt Mechanics article: For example, a 1/1 creature, a 3/1 creature, and a 4/6 creature have three different powers (specifically, 1, 3, and 4). By contrast, if you have a 2/2, a 2/3, and a 3/3, you dont have coven because two of your creatures share power 2. If you have more than three creatures and a couple of them have the same power, that's not a problem for coven as long as there's at least three different powers among them
2 Rares With a chance for one of these to be upgraded to a higher rarity
Its a small sacrifice that gives the control deck an eighth card in their starting hand which is perfect for an archetype thats all about card advantage
Theres also a hand smoother in best-of-one