I think another thing we have to consider is tagging. The Ducks might not be able to add a large salary with term till we move a long term deal. With both Fowler and Manson extensions already affecting our tagging space. Adding Duchene would significantly cut into what space we have left after adding essentially 5.6 mill to next years cap with the extensions. This limits BMs ability to resign in season Montour, Ritchie, Kase, Wagner, and Cogs. Now most of those guys are RFA so we could wait till the summer to resign them but Cogs would be hard to find space for. We only have about 15.8 mill in tagging space and subtract 5.8 from the raises for Manson and Fowler. That least roughly 10 mill to add long term salary in the form of extensions and added players. If we keep Vats this year and added Duchene we would essentially have to wait till we moved Vats before we could resign our RFA's/Cogs. That could hurt Vats value a bit as teams would know we would have to move him to make room. Though that might be the case anyway. Ideally for me, I would include Ritchie in the deal for Duchene. That reduces the number of players we have to resign and he can be replaced in system by Jones or Fiore. You move Vats at the draft which adds 4.8 mill to the 4 left in tagging space after getting Duchene to resign Cogs. We then work on the RFA's after July 1st when the cap goes up. Even with that I think BM would ask for retention on Duchene. It would still be tight to get replacement players in that space. The other option of course is to let Cogs walk in FA which I'm not a huge fan of doing.
I'll stick by my prior assertion - it is very unlikely the ducks can afford to bring back Cogliano and given his age, they shouldn't really stretch to do so. Currently the ducks have about $65M in salary committed to 2017-18. With the remaining money, they need to re-sign RFAs (Kossila, Ritchie, Kase, Montour, and maybe Shaw), and resign or replace replace Wagner, Vermette and a few other bottom six forwards. My guess is Montour gets a longer term deal (like Rakell Manson and Lindholm) while the other RFAs get bridge deals. You can do the math, but even with a trade (maybe Vats) there's not much left for Cogliano - probably not enough to pay him what he currently earns ($3M). And no doubt he'll want at least that, with term.
I think now is the time for the ducks to consider trading for an elite cost controlled forward (preferably a center). Getlzaf, Kesler, and Perry are set for steep declines. Even if you think Steel eventually steps in to fill the gap, they need to find more young talent if they want to keep their defensive core and Gibson together for the next 3-5 years. Someone like Sam Bennett (not saying he's available) would be ideal. Duchene or RNH would be a play for now (not averse to that), but they don't fit in with the ducks long term because I don't think the ducks can afford to re-sign them (unless Kesler retires due to injury). I don't think Edmonton would trade RNH to the ducks unless the ducks massively overpay.
The price will be high, but I'd love to see the ducks aggressively pursue a young center even if it means giving up Larsson/Vats and a first round pick (or some other hefty combination of assets). I think now is the time to bolster the lineup (a young center who can be a 2/3 now and more later) and hedge for the future.