Mono Green Landfall wants to go bigger than us with Mossborn Hydra and Mightform Harmonizer; Clarion Conqueror flies over the ground stall, and its static ability stops activated abilities of creatures, which shuts off Llanowar Elves' mana ability and Keen-Eyed Curator's graveyard exile. It does not stop Mightform Harmonizer's warp, since warp is an alternative cast cost and not an activated ability. Keep in mind that it also turns off our own activated abilities, such as Liliana the Faultless and Ajani Resolute's loyalty abilities. Starscape Cleric's flying attacker is cute but we don't need the reach here and it can't block, so it's the easiest cut. Curious Farm Animals gives us a cheap body that still gains life on death and can destroy a Sapling Nursery or Earthbender Ascension, and Soul-Guide Lantern or Torpor Orb if they bring those in from the board. Its sacrifice ability is an activated ability of a creature, so it won't work while Conqueror is on the battlefield. Keep the lifegain engine intact since it out-values their grindy landfall plan over time.

Dimir Midrange is full of our worst nightmares: Enduring Curiosity, Kaito, and countermagic like Spell Snare and We Say Thee Nay!, so Duress proactively strips their interaction or Kaito before we commit threats. Strategic Betrayal is a reasonable inclusion here, especially when they have only one creature on the board. They choose which creature to exile, so it won't reliably hit their best one, but it also exiles their graveyard. Moseo comes out since its 2/1 body dies to Bitter Triumph without enough payoff against a deck that doesn't flood the board (Shoot the Sheriff can't target it, since Warlocks are outlaws, but one clean removal spell is enough). Starscape Cleric is too fragile against their removal-heavy plan to be worth the slot.

BRG is a creature-heavy midrange deck with sacrifice synergies (Callous Inspector, The Sackville-Bagginses, Umbral Collar Zealot) and powerful threats like Smaug the Magnificent, so proactive discard is good at stripping their key noncreature spells before they can leverage them. Duress strips removal like Requiting Hex, Stir Up Trouble, and The Misty Mountains Cold's value engine before they matter. Strategic Betrayal makes them exile a creature of their choice along with their graveyard. They will usually give up their least valuable creature, such as a Greedy Freebooter or Callous Inspector, so it is a modest edge-case effect, but exiling their graveyard can still blunt Lively Dirge reanimation. Erode is cut because it only trades up against planeswalkers or creatures and gives them a free land, which is less valuable against a deck already flooding the board with Treasures and Lander tokens; Lunar Convocation comes out since its slow incremental drain is too passive against this aggressive-midrange clock.