You can have all the classes you need in a KQ but that doesn't mean they'll be useful.

I haven't done the MD since the patch so I have no idea how that goes about now. I know that before I was able to tank it as an Archer with little to no problem and kept aggro too (until the fire breath that is).
And yes, you can pull with a Mage. Archer is nice
r because they can possibly DoT it while it's chasing after them. That's probably the only difference aside from a possible AoE accident that'd more than likely kill the mage in one hit. I think that to this day Mara KQ is by far the most difficult in terms of having "smart" people.