First I’ll say I do it on my Protection Paladin and I’m able to overcome everything that’s been thrown at me so far, however I’ve seen some really really hard difficulty curveballs that have me wondering how any non-tank class could get through it.
Like Layer 3 of Mort’regar, I’m repelling from platform to platform, landing in clusters of elites, with more elites teleporting on top of me, I have like 3 interrupts I can use, with minimal cooldown between them, along with a bunch of emergency recovery options. I had to blow through nearly all of them.
Now, I made it through, but I highly doubt many, if any non-tanking classes would have managed to recover from that. It’s certainly not unreasonable for it to be difficult, but if others got the same experience that would have truly been impossible for them.