Rummaging, mana-less sacrifice and removal on an aggressive body are asking a lot from an uncommon, and Bloodtithe Harvester answers it well
The land ratio you're looking at should be about seventeen lands to 23 nonlands
In practice, you want to level up your creature only as many times as it takes to get to the final level
This is why there is such a premium on flying and unblockable creatures - they are hard to kill in combat, the #1 way to kill creatures in sealed and draft
The first official crossover set with Dungeons and Dragons, Adventures in the Forgotten Realms will introduce many of the tabletop RPG's famous characters and monsters to the trading card game
More importantly, Orzhov is a better color combination for token-aggro, making this a more potent threat