Maelstrom Pulse answers any nonland permanent, giving us a clean way to deal with Smaug the Magnificent or The Sackville-Bagginses regardless of protection abilities. Strategic Betrayal exiles a creature and their graveyard, which is strong against Lively Dirge-fueled recursion and denies Biotech Specialist or Rottenmouth Viper synergies. Requiting Hex only kills mana value 2 or less, missing most of Jund's bigger threats like Smaug or Chandra, Spark Hunter, so we trim it. Duress is weaker here since Jund is a creature-heavy aggressive-midrange deck without much vulnerable interaction to strip.