As odd as it sounds, I feel like this is probably playable in a Goblins shell. I know few folks have tried out Grixis Gobs, but the only substantial weak point of the deck is that it's full of tiny Goblins who can't do combat. Since you run Tinker and Welder anyways, this turns a graveyard full of dorks into 4/4s with substantial ETB triggers. Not claiming Gobs is viable with so many Ballistas around, but this is the Tinker target Gobs has been looking for. Huge upgrade to the deck.
This may also be viable in various shops builds, too. Ravager and Ballista are cute with a 4/4 base.