Selesnya Company is a fast, go-wide creature deck built around Collected Company, Elvish Mystic, Llanowar Elves, and payoffs like Ouroboroid, which grows their whole team with +1/+1 counters, and Elspeth, Storm Slayer, which makes and doubles tokens, so proactive disruption before they can curve out is key. Thoughtseize lets us strip a key mana dork, Archon of Emeria, or Collected Company before it snowballs into a board we can't stabilize against. Ozai's Cruelty deals 2 damage to the opponent while also forcing two discards, punishing their lower card count after a fast start, though they choose what to discard. Claim the Firstborn is unreliable here since it can only take creatures with mana value 3 or less, so it can't reach Ouroboroid, and the small creatures it can take, like mana dorks, give us little for a one-turn steal. The Sackville-Bagginses is a low-impact sacrifice piece we can cut without touching our core engine or mana base.