Engineered Plague choosing Goblin cripples the vast majority of their creature base (Goblin Lackey, Matron, Piledriver, Ringleader, Warchief, Siege-Gang tokens) by shrinking them all to -1/-1, which kills the many 1-toughness Goblins outright. Snuff Out is free removal (pay 4 life with a Swamp) for Siege-Gang Commander or Goblin King before they snowball the board. Hand disruption like Unmask and Duress is weaker here since this is a low-curve aggro deck that floods the board rather than relying on one key card, so we trim some of it for proactive answers. Keep the reanimator plan intact since Scion of Darkness and Akroma easily out-race their clock once stabilized.