If you have 2 tanks (WAR + PLD or WAR + DRK since no one uses DRK + PLD), you have the WAR open to build the biggest burst enmity lead, and then swap so that DRK/PLD never need to touch RoH/Power Slash.
In terms of going solo, it doesn't really matter - as long as you can maintain hate then all tanks are fine. PLD has a struggle in this regard in terms of DPS, however it being able to actually hold hate if it needs to isn't an issue.
