It would just be an art change to make all of the daggers with reach 2 attacks in to spears. The daggers that have Steps built in to their attacks make sense as daggers. But dood, Strong Stab on daggers even has a pic of a spear on it. It just feels wrong to have daggers reach further than axes. Axes = Cleave Spear = Reach Dagger = Step Sword = Pierce Just an art change. Everything is perfect.
Maybe they're throwing daggers? Still think that would entail an art change, however... Maybe it represents the amount of mobility a dagger provides. The hero has enough time in their "turn" to take a step and stab and then back off.
Don't get caught up on these things or you will go insane there are also swords with range 2 attacks and one of the best step attacks i have seen has a sword in the art. Not to mention warrior weapons that give you fire magic.
This is likely. I understand dagger attacks that give range, but they should move you forward then back, not just give you the range. The idea being that if there were counter cards that got a free strike on someone moving in on them from the front it would be effected. Rear attacks would not be as it's a sneaky attack.