DRK + War

[Sokerimuro]

What no one seems to bring up here, and is of utmost importance in a discussion such as this, is the Golden Rule of tanking. Repeat after me:
Spikes kill tanks!
Nothing else. Tanks do not die to autoattacks or steady boss damage. Unless the boss has powerful repeating physical cleave or exclusively physical tank busters RoH str debuff does not compete on the comparison.
It all boils down to what kind of damage the predictable spikes deal/what is the raid damage made up (in most cases this is magical)/does your setup have a MNK. I am MT of our static, and bringing up my DRK to use both PLD and DRK maintank whichever fits better the encounter at hand. Also our static does not sport a MNK.
Dark Knight definitely has the tools and the potential is there.