This card usually goes for $10 or more
But back to size - and why it matters
This means you could put this mana into something like Urza's Ruinous Blast or Karn's Temporal Sundering at a pivotal moment
I'm not going to talk too much about any of the vanilla creatures that don't do anything, but mainly the cards I think will imapct Khans of Tarkir / Fate Reforged limited the most
Since we have so many 3C spells, support spells like Omnath, Locus of All and Meeting of the Five are tremendous value here, along with treasure generation from Widespread Thieving and repeat burn with Mana Cannons
One thing that the Cavalry has over Craterhoof, at least in a vacuum of single color identity, is that White does get a smattering of blink and flicker effects, making this card far less survivable in the long term if it can be used again and again