This is a different topic sort of, but when fighting the boss characters it always seemed to me that my DK character who I made a warrior was much more effective than my hero character who was a mage. I also noticed the same thing in DD. I was a mage, but when fighting the bosses I needed to use a weapon instead of my magic. I think this needs to be balanced better for D2.
I do not think it needs to be further balanced.
It's the other way arround for me. Although I often use melee and bow, I find that Nature Magic and Elemental Curses are invaluable against bigger foes.