Gruul Ponza plays almost no artifacts, enchantments, or red/blue spells that our color-restricted sideboard cards can interact with, and Gut Shot's damage is too small to matter against their large green creatures like Annoyed Altisaur and Bramble Wurm. Our best plan is simply leaning on the unchanged maindeck: Counterspell to stop their land destruction (Mwonvuli Acid-Moss, Thermokarst) and ramp, while the mill-cantrip engine builds toward cheap Tolarian Terror and Cryptic Serpent to outrace their clunkier draws. Since none of our sideboard cards have legal or impactful targets here, we make no changes and trust the core engine's raw power level and tempo advantage against a slower ramp strategy.