Theres a simple fix... Focus the cards and all aspect spells as well as cooldowns for AST..Turn diurnal into healer stance + 4 healer specific cards. And turn nocturnal into cleric stance+ 4 support specific cards... And remove the regen +shield ... Instead have a buff which cause all damage taken from the last 5 seconds to restore a portion of the damage delt at the time

Example u cast aspect benefic on tank and he recieve 10000 damage spike within 5 seconds ur aspect benefic will heal for a portion of that damage afterwards like 35-45% of the damage recieve in 5 seconds so the tank will get healed for 3500 or 4500 (example numbers this may need adjusting)

So for healers it will look like this

Whm - burst / hots / high healing
Sch - mitigation / medium healing / pet support
Ast - reverse time healing / medium healing / buff support

This would not even be op and makes use astrologians with time magic, and fortune telling