I'm not a mage but I'm thinking a good strategy for the party to develop as a whole would be to take a little more personal responsibility for your own health, especially the war disciplines. If you're a random melee DD and you get hit by an AoE, don't be afraid to pop second wind or bloodbath+attack. If some people can take care of themselves for minor heals then the actual healer can focus more on the tank or those oh shit situations. Every bit helps here.

However communication is key here so the mages dont waste MP on someone who is going to heal themself.