Domain Zoo is an aggressive deck full of small, efficient threats (Wild Nacatl, Ragavan, Territorial Kavu, Scion of Draco) that Dismember's -5/-5 can answer cheaply, buying crucial time. Six is a resilient blocker with reach that survives their burn spells like Lightning Bolt and Tribal Flames while generating card advantage. Summoner's Pact is too risky against their disruption suite (Stubborn Denial, Spell Pierce) that can strand the delayed payment, and Aftermath Analyst/Cultivator Colossus are too slow against this aggressive clock, so they are cut. This matchup is a straightforward race where stabilizing with removal while assembling Primeval Titan is the plan.