I mixed in a Witch Doctor for the 4th slot, as I was getting frustrated with the lack of defense. It's odd if you add too much defense the screen lags. Not freeze, everything just stops moving. This is typically caused when 8+ Slow Time bubbles appear on the screen.

With a WD in the mix, everything is frozen in place and the pets help offset the initial barrage. Wiz dps btw is super high. Elites / Champions and even Rift Guardians drop quite fast.

I'd like to see how this scales in higher rift difficulty but for T6 it made it much smoother for me and less annoying deaths.