1) remove 1/2 the healing abilities. Give them a modest stock cure 1, and a few resource-managed cures that can’t be spammed. So healers would need to heal as needed rather than spamming/100% topped off at all times.

2) give them dps rotations that are entirely fueled by healing correctly/efficiently or fuel healing itself. Similar to sage. Robust dps rotations.

3) have it so healers actually run out of mp if they do too much too fast. Not a problem as a burst option, but more of a longer fight resource management problem where they might need to just chill and recharge mp mid fight.