Should penilties be stronger on random acts of violence?

Stronger then they are of course, Measure 11, in Oregon, causes for mandatory minimum sentences for cases of assault where the assaulter uses an object (knife, pool cue, ashtray, bike, you name it) it can carry a ten year minimum.

People tend to get hurt a lot worse when there is an object in hand. But say, I throw an ashtray and it hits you in head, you get stitches, should I go to prison for 10 years? I would not get such a harsh sentence if i broke your arm.