Well, it wasn't just Rondo who got Shaq open looks. It was having Shaq as the 5th offensive option *and* having a point guard with court vision and passing skills to get him the ball in good spots.
If we brought Dwight here, the point guard would remain the same. However, the big question would be whether the Celtics had the other pieces around him to be successful. Right now, I don't think Jeff Green + Avery Bradley is a competitive foundation.