While Luke doesn't have Call to Action, he has +50% Counter Chance, +50% Critical Avoidance, +50% Defense, +100% Tenacity, and gains 10% Turn Meter whenever another Rebel ally takes damage.
While R2-D2 is active, all allies gain 10% Critical Chance and 10% Accuracy. While R2-D2 is active, whenever a Light Side ally scores a Critical Hit, dispel all debuffs on them.