Nutivaara > Carlsson > Harrington
The only thing (IMO) Carlsson has over Nutivaara is actual physical size and reach/stick length. Problem is that the dude, at least not yet, hasn't learned to use this size and reach advantage he has on most, to his actual advantage. Quite frankly I think Carlsson could use time in the AHL to work on his skating and get used to the physical play and small ice. I really think the only way Carlsson can prosper in the NHL is if he plays in the mold of a Prout. He needs to focus solely on defense, along with the need to DEVELOP and play with as much of an "edge" as he can. In my opinion, of course.
Nutivaara is just as good or better defensively as Carlsson or Harrington. His vastly superior skating and offensive instincts and ability also seem to mesh much better with Murray, or the 2 other "common" or possible D partners, in Johnson or Werenski, when (not if) Murray moves up a pairing.
I see their future (NHL careers/on CBJ or not) shaking out like this: Gavrikov (def d man) = Nutivaara (off d man) > Carlsson (def d man)