I'm more concerned about this from a lore point of view regarding SCH, since Leeches was 1. a skill you got through a quest, 2. was story-used in future quests. I can imagine they'd just make you cross over Esuna and use THAT, but that's just... meh.

Ideally, most healers would cross over all the defensive skills for a first time through content, or at least look it up before giving up on it, then once they know what's what they can move things about. But I think most people will either not realize they need to do that, or go full bunkers offensive from the get-go and wipe their team a couple of times depending on mechanics.