Replenish doesn't attack with creatures you can profitably Dreadnought-sacrifice into, so Stifle is mostly dead here since their key triggers (Attunement bounce, Parallax removal) aren't the kind Stifle wants to interact with early. Pyroblast is excellent against their blue counterspells and can destroy Attunement before it cycles their deck. Keep Duress and Cabal Therapy maxed to strip Replenish or a counterspell before they can combo off, and race them with Reanimate/Shallow Grave before Opalescence-Parallax Wave locks the board.

This is a mirror-adjacent matchup where their entire plan hinges on Stifle/Vision Charm protecting their own Phyrexian Dreadnought, so our Stifle and Vision Charm already do double duty both offensively and defensively. Our sideboard has no good answers to their counterspell suite (Annul only hits artifacts/enchantments, not their blue spells), so the best plan is simply to keep the maindeck intact and focus on being the faster, more disruptive deck. Duress is live to strip a counterspell before deploying our own Dreadnought or Hermit Druid plan. This is a race decided by who assembles their engine first, not a sideboard matchup.

Sylvan Safekeeper shields our reanimated Dreadnought or Sutured Ghoul from their removal-light but aggressive Goblin horde, letting our one big threat survive combat and racing math. Stifle has minimal value here since Goblins mostly just attack and cast creature spells rather than relying on key activated/triggered abilities we can profitably counter (Goblin Lackey's trigger is a rare exception but not worth a dedicated slot). This matchup is a straight race: our Hermit Druid/Reanimate plan should out-speed their Goblin curve if we keep our key piece alive, so prioritize protecting the reanimated threat over interacting with their board.