My 2nd rift 5 man dungeon

[Apatheist]

While it may seem, logically, like having 5 DPS (or 4 DPS and a healer) increases your clear speed - it's actually much faster with a tank. A tank allows you to gather up multiple groups and AoE them all down.

Here's a video of my group. Similar to yours except that I used 4 Clerics and a Rogue tank. I'd overpull a ton, wait until my health got low and then use a cooldown (Rogues get a ton of cooldowns). Doing this, you can clear whole rooms in one pull quite easily.

http://www.youtube.com/watch?v=BA_cBqIbOgI

PS,

I later discovered there's a much easier way to clear the last boss of Runic Descent. If you stand at the entrance and just move your alts behind the wall when she starts casting Wave, you take no damage at all. This was one of my first clears :P