Nah, you should be able to do just fine without heading off to HoW first. I did this fight on Insane at roughly the same point (in terms of average party level) without too much trouble.
The last two posts (mine and Azred's) in
this thread have the key information and tactics for taking out the deadly tarnished sentry + fire salamander combo.
Don't be shy about retreating, healing, resting and going back in if you have to.
[ 01-14-2006, 02:21 AM: Message edited by: Aerich ]