» Sat May 12, 2012 4:07 am
Not a definitive answer BUT:
Source: Prima offical game guide
The guide lists several archetypes and suggests how to build them. One of the archetypes is named "the Assassin". It lists essential perks and armsman is one of those stated as a must have for the character, who is not only pictured wielding daggers, but states specifically to use them daggers after getting the assassin's blade perk. also, here's a quote. "as an assassin you need fast, powerful, offense to cut down your foes before they can retaliate. take perks in one handed and snead to increase your damage output as much as possible"
so to me that means yes, it does effect daggers.