take for example a +3 holy silver greataxe of greater evil outsider bane (a +7 axe, so 13.5 avg base, with 5d6 extra dice). Now compare that to common shroud boss beaters. Mineral 2, 15.5 average base with only 2d6 applicable elemental damage to the pit fiend or VoD boss, along with 1d2 slicing. The greater bane does about 8 more damage a swing.
Mobs would still be balanced towards a weapon like this, but shroud weapons allow everyone a chance to have a nice all purpose weapon, and still be competitive to the lucky or rich player with super bane weapons.
Everyone can get a shroud weapon with a little effort, very few people can land a real beauty of a greater bane or awesome stat damager