Iron Maiden was a melee damage return, right? The game was just as much about spells and ranged combat as it was about melee combat. On higher difficulties, it is almost certainly designed to prevent solo'ing. There are physical immune and magic immune and individual element immune monsters all over the place. You couldn't fight your way through without a mixed group of characters. You needed casters and rangers and tanks. You needed physical damage, fire damage, lightning damage, ice damage, and magic damage. Doing Hell Baal runs, even with my level 87 barb who was nasty, sometimes there were spawns at the throne that I just couldn't fight, and I'd have to hang back and let a caster deal with them.