Campbell was a one-man breakout and a one-man entry into the other team's end. He did it a ton. Right now, the Hawks struggle accomplishing both of those tasks with all five players. That's why he's missed.
His puck handling/vision is what they miss. Not his "offensive defenseman" role.
You just described an offensive minded defenseman to a T and then well, not sure where it went to, but you say that is what the team is missing...
I contend what is missed is being able to take away chances from the other teams, and more than likely from high percentage areas (I'm at a disadvantage in that I can't see entire games -and the highlights will only show when they get scored on for the most part).
I'm of the opinion that the team is more in need of a guy like Steve Smith than some puck moving defenseman who is kinda weak on positional defense -such as taking away the high percentage shooting lanes. Or at this point a couple of them... Hard to find, though... and apparently nothing like that on anyone's trading block.
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Edit- to address Ice's loose puck ... I should also add that hockey is also how you, as a team, manage the other team's cough ups. . . however, since we were only talking about defense and give aways ... I limited it to that. Plus I was speaking in general. I don't think you can knock a team for coughing up the puck- as it happens in every game and everyone does it -no matter, the level... it is just that bad things happen when, you as a team, aren't managing the situation well.
I guess I like the Mike Keenan philosophy of team building better than Quenneville's ... only insofar is that the Keenan model emphasized team D from everyone (ok, granted it was also before the cap -but I doubt that would have changed Keenan's approach to the game ... as defensive focussed guys are generally cheaper to sign.
Oh well, my team good times or bad times... it's still hockey.