When I'm doing the Threat From Above group quest, it's pretty rare that there will be an actual tank. So I'll click my Outfitter button that equips two pieces of Tier-5 gear for the free mending and announce to the one or two other people in group, "okay looks like I'll improv pet-tank him". Hunter mark him. Flip a MD. Throw him in. Start a mend HoT. Wail with the MD.
I do this while still as Survival spec and still with my wolf. I know this isn't rocket science. It's a random mention. ;-)
Oh, and I upgraded my Tier-5 shoulders and gloves so they have nice stamina gems and dps enchants. I did that for normal hunter tank spec stuff. You certainly don't need to tank for the Threat quest. There is room for kiting. But tanking is cleaner, easier, and quicker.