Mono-Red Prowess is a pure damage race full of burn like Burst Lightning and threats like Sunspine Lynx (which also shuts off lifegain) and Screaming Nemesis, so Redcap Melee and Scorching Shot give you bigger removal to answer their best creatures before they connect. Spell Pierce is weak since their curve is cheap and proactive, rarely leaving you a window where the tax matters. Boomerang Basics and Monstrous Rage are lower priority than hard removal in a matchup decided by who controls the board and survives burn-to-the-face. Keep your full removal suite like Burst Lightning and Reckless Rage, since this is a race where every point of damage prevention matters.