Quote Originally Posted by spelley View Post
It's to prevent WHM from going full preventative tank in-battle for the whole party. It would step on SCH toes to give them a strong AoE "shield"-style spell that is easily castable in-combat.
The question voiced is why SS II has a cast time despite the fact that it can only be cast out of battle. Sch remains largely solely responsible for party mitigation, excepting progression fights where the Whm needs to SS the entire party (i.e. T9 megaflare, or FCoB mechanics I've yet to encounter).