I'm torn on what he could use. There is the defensive side of things where I don't know if he's ever going to have the instincts to close with and contest space around his own net, to kill plays, etc.... And then there is the brilliance of his ability to move the puck up the ice which having the puck on his stick would emphasize.
Over the years of watching him, the guy who seemed to make him tick the best (covered for him around the net, killed plays, deferred to OP's breakouts) was Blankenburg at Michigan who was small but fiesty, mobile in his own right, and a little demon around his own zone. I can't seem to find an established NHLer who fits handedness and fit honestly. A guy who can kill a play and move the puck to him while not being disengaged to the situation at hand would be the wider scope.