You are right, the archers are like snipers. Is there anyway you can conjure to fight them off ? Now, what I did was to use sneaking and kill one by one with my bow but I agree with you, they are very accurate and too many. It is a hell of a fight especially if you are not that powerful at the moment which I believe nobody is when you are following Esbern and Delphine to the Sky Haven temple. Now if you are alone, it will be more difficult but if you are with them, you balance out a bit and if a dragon shows up, the thing gets more interested. In my case, the dragon showed up right at the bridge, before you get to the camp so I could concentrate on him before I faced the freaking camp but It was tough to kill that freaking dragon and everybody at the camp.