Izzet Aggro leans on burn (Burst Lightning, Reckless Rage, Screaming Nemesis) to close games fast, so Gather Courage protects our key creatures from their removal at instant speed and can save a blocker in combat, while Elder Gargaroth's high toughness dodges most of their burn outright. Tail Swipe is risky since Reckless Rage can snipe our creature for 2 first or Screaming Nemesis reflects damage back at us, so we trim it for the more proactive protection plan. Titan of Industry's modes are weak against a deck with few artifacts/enchantments, so we cut two copies to make room.