Read the kit on CLS again. They don't gain tm when they resist debuffs. They gain 5% when YOU resist a debuff from them. Furthermore, the 10%/5% tm is whenever CLS lands a debuff, and on his basic he attempts two and the expose from 3PO brings it to three. So if he is called during the mass assist, that's at least 15% tm for everyone--up to 30% potentially for himself.
Luke also gives himself 10% tm when other Rebels take damage while he is in defense mode.
So if your Chirpa resisted the expose from Han, they already gain tm. If your Elder attacked someone other than Luke, he gets tm. He goes next and either lays down three debuffs or you resist a few. Either way, it's enough to push R2 next.
