Engineered Plague naming Goblin shrinks almost their entire board by -1/-1, killing all their 1-toughness Goblins (Lackey, Matron, tokens, Fanatic, King, Tinkerer) and weakening everything else, which is huge against a tribal swarm deck. Diabolic Edict is useful removal that dodges any protection and can take out a key Goblin like Warchief or Siege-Gang Commander. Foil and Circular Logic are weak since this is a low-spell-count aggro-creature deck where countering a creature spell for value is less impactful than removal or Smother, which stays in. Keep Smother and Sickening Dreams in as they efficiently answer the deck's many small-toughness threats.