This is true -- to an extent. The Sedins don't generally set the point up for plays on the PP though. They use it as a passing outlet to relieve pressure when teams press them too hard in the corners, which opens up ice for the defense. Garrison is more of a traditional PP shot, in that he sets up and tries to find open room in the middle of the ice to set up for a wicked one-timer.
Unless it's a 5 on 3, I think he's wasted on the first unit. Edler, too, for that matter. When Kesler is back I'd like to see him on a 2nd unit with Garrison and Edler, or at least one of the two.