With a defense of 8+ and only two temples of the dawnbreaker, you have about an 80% chance of successfully avoiding an attack. With four temples it's 93% chance of success.
But even if you get out that many temples, you need a way to deal with enemy using more than 2 attacks. Temples are zone exclusive, and so are suppression orb and mordok's obelisk.
Plus, there won't be room for temple of light.
Priestess has a lot of access to healing and daze/stuns.
I recently made a tanking forcemaster AND a tanking priestess playing a rather similar strategy in two different ways:
Priestess doesn't have access to forcefield, and doesn't rely on defenses as much as forcemaster because she has access to healing, extra attacks from Temple of Light, and dazes/stuns. If you play her as a tank, she WILL take some damage, and that's okay, because your dazes/stuns and temple of light's attack will buy you time to use your action or quickcast action for healing.
The forcemaster of course relies on enchantments, like forcefield and mind control. When forcefield is down she still has defenses. Her extra actions come from her use of cheetah spy eed, ballista and dancing scimitar. And when her forcefield goes down, she still has defenses. A single temple of the dawnbreaker is useful here. The priestess probably only needs two.
The forcemaster build is working pretty well for me right now. I have yet to test the priestess. I'll probably post them both on here eventually.