Boros Dwarves is an equipment-aggro deck relying on Leyline Axe, Lavaspur Boots, and Dragonfire Blade to buff creatures like Dwarven Mauler and Kili the Resourceful, so Cathar Commando is excellent, trading in combat and sacrificing to destroy a key equipment before it swings a race. Erode removes their biggest equipped threats (Thorin, Mountain-king or a buffed Dwarven Mauler) cleanly at instant speed. Goldmeadow Nomad and Aunt May are too small to block their equipped attackers profitably and don't generate enough value here, so they're cut; the lifegain engine stays fully intact since racing their aggression with life gain is the primary win condition in this matchup.