BRG is another creature-heavy midrange deck, so Gideon the Oathless punishes their steady stream of threats (Gene Pollinator, Greedy Freebooter, Biotech Specialist) with incidental damage on every creature they land. Duress proactively takes their removal (Requiting Hex, Stir Up Trouble) or their own Strategic Betrayal before it can interact with your board. Samut's haste is less important in this grindier mirror where card advantage and resilient bodies matter more, and the second Stinging Vitriol is a weak discard-and-burn effect compared to Duress against a deck with plenty of removal to strip.