It seems like a lot of people want Astro to change, and I agree with that statement, but I personally believe the way to do this is to take them out of the shadow of white mage and scholar and give them their own niche.

By giving them a 'white mage' stance, and a 'scholar' stance, by very design they're going to be in constant competition with the other two jobs as to which does x job better.

Personally as it is now, I believe astro/scholar groups to be the best, as astro, regardless of lower potency spells,can solo heal just as well as a white mage can, with just a little more required effort, while also having the added bonus of their cards to increase the groups' dps. Without the freecure's or mana reducing traits/abilities that white mages have, I (personally) find that Astro's have no problem with their mana management abilities as well.