Everyone (even us) mills ten, then we get to reanimate something from each graveyard
Geometric Nexus Geometric Nexus scales well since it counts spells cast by all players, but the costs are still too high
Commander has a ton of powerful ways to generate a bunch of mana, and turning that mana into cards, life, and a Jellyfish Hydra Beast that flies and tramples is pretty much everything you want to be doing in the format
These are further divided into four tiers each with the exception of Mythic division which is divided into percentiles
It could command too high a cost when the other guilds dont have to pay a premium and can force the Orzhov player to two-for-one themselves just to stay alive
The 4/2 Plant tokens address a common problem with ramp cards, that they make you pass the turns where you cast them, giving Regrowth a leg-up on the competition