We did not finish the mission, but we got pretty damn close to doing, right down to the last group which refused to die after numerous attempts. We cleared the first two groups in about 6 minutes, and then kept retrying the last one over and over again for approximately 20 minutes before giving up and dying. We found out Ranger interrupts are easily countered by enemies using Throw Dirt, and we lacked some burst damage in general to take out the priest between interrupts. Does it mean what we attempted is impossible? Hardly, with a little more coordination and teamwork it would've been a breeze.
And why do I bother making a post about *almost* succeeding in doing Thirsty River mission? Simple enough, because this is the group setup we had.
I'm so tired of people complaining about Rangers being useless in groups, and how they'd rather have another Wamo instead, hell, I've had people leave groups because someone let me in when they already had a Ranger. Rangers may not the end of all class, but they are far from the useless weak class most of the idiots around make of them.