Devoted Combo wants to assemble Devoted Druid plus Vizier of Remedies (or Badgermole Cub synergies) for infinite mana, and Containment Priest shuts off any attempt to cheat creatures into play while also being a reasonable early body. Rest in Peace is more marginal here since their combo isn't graveyard-dependent, but it does disrupt Nature's Rhythm's harmonize mode and any Agatha's Soul Cauldron graveyard shenanigans, making it a worthwhile one-of swap. Stubborn Denial and Spell Pierce are cut since the combo pieces are creatures that avoid noncreature-only interaction, so tempo counters are weak. Prioritize racing with your low curve and holding Leyline Binding for Devoted Druid or Vizier of Remedies to break up the loop before it starts.