I have done this mission before at level 16 with henchmen so I kind of knew what I was suppose to expect. I also ran it without a loss of life from me or henchies but I died like 6 times this round.
Try #1 - #3
The White Mantle Knights get slaughtered by a Jungle Troll and friends before I even leave the starting point. I lost my 2 added tanks. As soon as I entered the first area, the pods pop with 3 scarabs and a tree. No problem we just barely survive. I move forward to the next clearing and see red dots headed my way so I back up. WTH they charge from outside my aggro zone. To top it off 2 pods pop to assist the scarabs. We back up but now there is another group charging.

I don't see the point to have 12 and 18 Scarabs charging when I fire one arrow. The groups were coming from beyond the radar for some reason. I seriously think it was bugged. It was just a wall of red dots on the radar after I fired an arrow at one mob. I would hightail back to the previous area and they just swarmed me and the henchies.
Try #4 - We got past the nasties and past the horsemen but when I got to the top of the frist hill,


Try #5 We cleared the way to the first cut scene my Mantle Knight survived to get us past the nasties but now the next part is just down right stupid. There are 4 groups of horsemen (what ever they are called) Each group is spread out. I watch the pattern on the radar and decide that the one group is far enough away from the other so I pull the nearest group. The protector is almost right next to my bip but when I fire I am running off in a different direction? WTH!? Lagged! the dots are way out of range. Hit escape but now we have two groups to deal with that be 4 warriors, 2 protectors and 2 hunters. We almost have them beat working on the last warrior when the next group decides to wander through. Well my healer and both fighters are dead and I and the others are beat up really good. So it was not even a fair fight.
Try #6 was a rinse and repeat of #1.
I came here to vent because I was down right angry at the time.
My apologies.
I went back and the mission went flawlessly without anyone dying. Now that I think about it I must have had a bugged mission. I went through 13 levels with 2 deaths but in 2 days I have died 23 times. It just got to me.