My paladin this wipe quadruple oblitted with extra attack and legendary strike. I could tank very well and assist as a damage dealer. Legendary rally is insane. Righteous will wearing off must be a joke. Even if you happen to afk for 2hours and then try to kill Izmerelda, at legendary you likely won't lose faith. If so, just pop up holy quest and kill red dragon or statue of tahkisis for instant faith >1000. The only thing that sucks about paladins is slam. The damage is great, the spec is great, it never lands. Aside from you whiffing 9.5 times out of 10, numerous mobs are immune_disarm which makes the skill fail. Otherwise, paladins can solo fairly well, and are valuable groupmates in any zone.
Barbarians really aren't bad as supplemental characters. Into the breach removed the auto rescue from wardance, and assail does great damage. I've had a non-tank legendary barbarian before who tripple oblitted(not impressive by todays standards), and was fun to play. The problem is that people think if a barbarian is in a group he should be tanking (even though a paladin and DK can often tank better).