I will restate some of the stuff I've said before while I can.

I really think AST should be a Heal-Over-Time or Reactionary/Time-Delay healer.

Diurnal sect would make heals HoTs while Noctournal sect would turn them into reactionary (Buff has X stacks and lasts for a long time, upon taking damage target loses a stack and gets a heal. When 0 stacks or time runs out, buff fades) healer or time delay (like Earthly Star)

This would give SE and the AST more opportunity to do things with their cards while the healing is being taken care of over a duration. Also duration extending abilities would work on their heals which just makes this type of healing make even more sense for them.