Just silliness here, but what if Astrologian gets abilities similar to FFX-2's Lady Luck...

Such as:

Clean Slate - Restores 25% MAX HP and cures negative Status Effects of user.
Auto-Life - Automatically revives an ally the next time they are Knocked Out.
Luck. - Crit chance up on self.
Felicity - Raise Crit chance up on all members of PT.

These could be interesting, and different from current healers.
/shrugs/