I think it's very important that they stick with this Cehlarik-Krejci-Pastrnak line, and that it works out. It completely changes the landscape for wingers IMO.
Trying to find a winger to fix the dysfunction between DeBrusk and Krejci is hard. You need someone that's a good passer, someone with a high IQ that's going to want to cycle with Krejci AND you need that guy to be a legitimate play driver in his own right so teams don't just key on Krejci (in the same way that 37 has 63).
Mark Stone could be that guy, but I don't have a lot of confidence in anyone else on the trade bait list short of Brayden Schenn and I think that ship has sailed. I don't think Saad is enough of a play driver. Kreider drives play but isn't a good passer...
BUT, if that equation changes. If the Krejci line is fixed with 22 & 88, then you're looking for someone to play with Bergeron and Marchand. Now all of the guys on the trade bait list are viable options because 37 & 63 can play with almost anyone. They've played with LH'd RW's like Recchi and Smith, they've played with elite skill RW'ers like Seguin and Pasta... Last night, Heinen played the role of net front guy and had multiple scoring chances off tips and screens and they had some success with lesser big body talents like Connolly and even Backes for stints over the last two years.
A guy like Ferland would probably make the Krejci line worse, but he'd be an absolute force on the Bergeron line where he wouldn't be asked to drive play, just create chaos with his physical play. A guy like Brandon Saad is hit or miss for me on the Krejci line because I don't see him as a play driver, but on the Bergeron line I could see him being one of the best complimentary players in the game.