Tireless Tribe's deck is built around aggressive green/white creatures like Arrogant Wurm and Basking Rootwalla fueled by Survival of the Fittest and Wild Mongrel discard, so an extra Swords to Plowshares gives more clean answers to their biggest threats. Trim one Wild Growth since racing on mana is less important than stabilizing against their aggression, and Elephant Grass is only middling here since their creatures are nonblack and will often just pay the {2} tax with their card advantage engine. Keep Parallax Wave and Solitary Confinement as your primary answers to their board of efficient creatures.