i think DRK will be mp based more than war and pld. it will have a huge mp pool instead of pure hp like WAR. these mp will somehow be used as a shield aka hp or mitigation. but since its a new class itll likely be way more polished out than WAR or PLD. and at release i except DRK to be stupidly good compared to the other two. however SE will nerf it about 1 patch later to bring it in line again. new addon classes on mmos tend to always be OP compared to OLD ones since it boosts sales for the publisher in the end tough they will be balanced somehow.

drk will have either better mitigation than war in that case it has to have worse dps otherwise why play war ever again?
OR it will have superior dps to war and pld but have the lowest amount of mitigation of all 3 tank classes. it will either of those. otherwise why play WAR at all?^^