I think I came to the conclusion that people that were not having trouble with this part were running around the column in the center TO THE RIGHT. I'm not talking about getting to the end and then running right toward the archer on the right, I'm talking about that column in the center that you run AROUND and then continue straight. If you go right there, I think the one on the left will not shoot at you when you get to the top. If you go left there, the one on the left will shoot at you even after getting to the top and the section is simply not beatable.
That's what I think anyway, I didn't confirm. I just know that I went left there 100% of the time, and then when going right at the top I would get shot in the back 100% of the time and die. At least 2 other people confirmed they always went right in the center, and didn't have problems.