Abzan Greasefang wants to assemble Greasefang, Okiba Boss with a Vehicle in the graveyard, then swing for value; disrupting their hand and graveyard plan is more valuable than our own marginal synergy pieces. Thoughtseize proactively strips their combo pieces or removal before they can deploy Greasefang, Esika's Chariot, or Thundering Broodwagon. Go Blank exiles their graveyard, stopping Greasefang from returning a discarded Chariot or Broodwagon while also disrupting Overlord of the Balemurk and Cache Grab value. Claim the Firstborn is weak here since their best creatures (Greasefang, Professor of Symbology) don't want to be stolen for damage against a deck full of removal and blockers, and The Sackville-Bagginses is a clunky sacrifice piece we can trim for more focused disruption without touching our mana base or core sacrifice engine.