The added advantage of taking daggers away from the Gladiator class, and giving them to the Archer class as a weak sub-weapon, is that it opens up the possibility of an additional Job for Archers down the road. Namely, those Archers that choose to specialize in their more stealthy Archer abilities and dagger use more than the average Archer.

An Archer that chooses such a specialization would be a Thief, no?