Add magic. If you fight under Heroic Might + Frenzy + Haste and if you have the Fury trait then the damage caused by your weapons can be about four times the maximum damage caused by the weapon. Examples:
Wizard's Blade, blessed, damage 20 - 74. Maximum damage seen: 287. Usual damage: 130 - 170. Hits below 100 have to be considered bad
Assassin's Dagger, blessed, damage 18 - 60. Maximum damage seen 217. Usual damage: 100 - 140. Hits below 90 have to be considered bad.
Also, I have found that the damage depends on your level somehow. Even if you have Dagger 12 and 2nd Weapon 12, you will not be able to reach the results above at low levels. As your level goes up, your score will improve gradually.