The Rock relies on discard (Duress, Cabal Therapy) and Pernicious Deed to strip your hand and blow up your board, so a second Ravenous Baloth adds a resilient Survival of the Fittest target that gains life against their attrition plan. Tormod's Crypt is helpful against Recurring Nightmare and Volrath's Stronghold, denying them a recursion target from the graveyard. Squee, Goblin Nabob is cut since it does little against a deck that isn't racing you on board, and one Quirion Ranger is trimmed for the same reason. Play around Pernicious Deed by not overcommitting more than one or two permanents at a time.