I successfully brought my group to it and we won. All we used for a henchie was Cynn, due to no nukers available. 3 monks, 3 warriors, cynn, and ranger.
I tried using henchies and I can get up to the named Suraat boss (not the wimpy level 20 Confessor final mob) everytime, but after that too many waves of Jade Armors come and kill my not too smart henchies - although smarter than some players.
We never died once until the Suraat come (cynn might have died once). The trick is to have 1 person at each cat and fire when they come, you can kill a few waves that way. I would be willing to assist but don't get home until 6pm EST. Name ingame is Elayne Sedai if you need help at that time. It is roughly 1.5 hours long, give or take. There is a definate route to take and I would be willing to help as this mission sucks.
The main thing is this is NOT a mission where people can run in blindly. You need a designated mob caller and a leader to lead. Also, do not get confused with the yellow ping the game gives for the inside city fight.
Server - YELLOW ping
Player - RED Ping
The problem is nobody ever listens and the rush in and get the king killed. There are a few parts where you need to wait for pathing mobs or you can get swarmed. Anyways, look me up if you need help still when I get home.