What does trading Turris for Duchene do for the Sens exactly?
Turris, according to leaks, isn't asking for crazy money. The issue is term. Ottawa doesn't want to commit to Turris for 6+ years because it makes things complicated. Ottawa really likes their other centers almost as much as Turris, Brassard and Pageau (Ottawa locals who hits it out of the park with their internal metrics) .Also, there is financials to think about, Karlsson and Stone aren't going to be cheap.
Taking that all into consideration, Ottawa has a few options:
1. Trade Turris for futures while trying to convince Karlsson to re-sign. (not ideal)
2. Lose Turris for nothing and run with a rookies next season. (Bad asset management)
3. Re-sign Turris and lose Brassard for nothing and hopefully the rookies will be read after next seasony. (Probably their best option, IMO)
4. Re-sign Turris and trade Brassard while trying to convince Karlsson to re-sign. (Also not ideal)
5. Some other option.
Ottawa is going for option #5. Getting Duchene gives Ottawa an extra year to let their young players develop and gives them extra options in the offseason. If Karlsson bolts they re-sign both. If he re-signs, they re-sign their preferred player and hope the rookies are ready.