On xbox, and I just went to take over that fort for the imperials, around level 28, and there are 2 archers standing above the gate that hit me in the foot twice, and im dead. Its kind of frustrating, god help my mage when I go there, get hit in the pinky and ill be dead.....
That Fort I think has naturally stronger archers. I can go take a fort down the road with the same occupants and come out smelling like a rose. I go to that one to join the Imperials, I die in seconds usually.
Add that with Master Difficulty, you got your problem. They do more damage and you do less the higher the difficulty.