Colorado moving Duchene without a 2C to play behind MacKinnon coming back makes no sense. Soderberg or Mitchell aren't 2C material.
Ottawa doesn't have a defender valuable enough to get away with acquiring Duchene without including Zbad. The only one who comes close would be Methot, and Ottawa would be foolish to trade him given his chemistry with Karlsson, and how Karlsson's play tends to dip when he is paired with one of the other LDs on the Senators.
You gotta give to get. So without moving Zibanejad, you'd be looking at something like Hoffman or Stone as the central piece, which Stone at the very least I'd hope is a no go from most Senators fans.
Even Hoffman doesn't really fit the Avalanche's needs if they are moving Duchene for a package. They aren't the same team they were two seasons ago, let alone one season ago. They don't have the same all world centre depth that they were known for now that they lost O'Reilly and Stastny while only adding Soderberg (who is likely to play wing most of the time anyways). Not re-signing O'Reilly for 7.5 per was a MAJOR mistake. Soderberg is making nearly 5 million right now, I'd gladly put 2.5 million more toward upgrading him to O'Reilly.
The logic of trading Duchene for Zibanejad + + to me is that the Avalanche have drafted really poorly outside the first round and now have multiple needs to fill that they should have filled via drafting. So if they can get Cowen (or Wiercioch if they are crazy and think he is a top 4 D), and a player like Puempel who could come in and play in their middle 6 right away, or even their top 6 if he finds chemistry with the right people, they'd probably end up being a better team both today and in the future than they would if they keep Duchene.
As a fan of both teams, as much **** as Senators management gets on this board, both teams makeup are night and day. The Senators have drafted so well that they have TOO MANY NHL ready players to the point where both this season and last season, they had to alter their lineup as to not lose NHL ready players to waivers (sending both Pageau and Puempel down to protect other players).
Colorado has gone crazy in the FA market with Soderberg, Comeau, Beauchemin, Iginla, and even Skille. Not to mention giving up 2nd round draft picks for players like Stuart and Berra, yet they still have multiple spots that need to be filled that they haven't done so through the draft.