I suppose the question of heavy armor vs light armor for your high deflection tanks is also dependent on what you need them for. For my party I just need my 2 tanks to keep the enemies engaged - I have enough damage from my druid/wizard/cipher that that I don't really need my tanks to do damage. They also have low might scores anyways - so I'd happily take a higher DR over more weak attacks. Besides, ever since my party hit 9 my tanks end up just holding position outside of the AOE kill zone that my wizard/druid have set up - a lot of the time they aren't even doing aside from standing pretty