Honestly I think WAR and DRK are very close in terms of defensive. The only difference is that DRK is easier to not overheal. Both use ehp mitigation via shields and/or heals. Not to mention tankbusters literally line up perfectly to your cds. P7S for example has equilibrium up for every aero. While DRK uses TBN to reduce dmg, WAR uses EQ to heal back that dmg. Also, EQ can crit so in some cases you are back at 100% hp after the hit and have a regen for the dot afterwards. That being said I still don't understand why DRK does more dmg than WAR if both are nearly identical in terms of ehp-style mitigation in savage.