Skippy if I remember correctly that was the dragon that got stuck in the wall for me. I just sat there for what seemed like forever and hit him with arrows until he expired.
For the ones in Dragansand I'm using Meteror Shower and Ice bolts with a bit of Sparks thrown in. That seems to at least slow them down some

I am currently in the Superior Temple of Baa doing battle with Sorcerers, Magicians and the ilk - they are not fun.