...Did you just copy and paste Smogon's set and description?
Dunsparce should never, ever, ever, ever, ever, EVER use Run Away. It has no use in battles that aren't with Wild Pokemon; i.e., it's competitive usefulness is zilch. Serene Grace is the only reason to use Dunsparce at all, so if you're not using it, there's no reason to use Dunsparce over another Pokemon. Heck, without Serene Grace you might as well use Exploud if you're looking for a normal type special attacker (Not that I'm suggesting anyone use Exploud, it's just a comparison). Dunsparce lacks the power to utilize a Choice Scarf effectively. Base 65 special attack is just terrible; Choice Scarf is generally used if you have something that has a lot of natural power, but could benefit from the extra speed to secure Revenge Kills.