Going with the current information available to us, these two seem to have some of the highest synergy.

DRK Grit interaction with the rest of its kit is an incentive for main tanking for the largest portion of a fight without any real drawback in stance swapping except for MP and a GCD, where as PLD is looking to be the new king of tank dps and seem like it would largely benefit from spending more time on sword oath.

In a scenario where slashing debuff will no longer be the luxury it is currently and will be far more accessible outside of having a WAR present, with the latter having a penalty in stance swapping and not bringing group utility to compete with either PLD or DRK, how do you think things will fare for WAR in a more serious raid environment?