What bothers me is that in order to wield a dagger and a shield, you have to devote Attribute points to both DEX and STR even though you can really only afford to have one high stat (as opposed to two medium ones) if you want the best high-level equipment.
They need a Trait which says "Shields require DEX to equip rather than STR." They can probably add in something about having only one swing per attack while a shield is equipped. But maybe not, if they want dagger to be awesome.
