Kane -> convince him to come team up as the two greatest USA players of this generation, plus a young American in Knies to form USA line. If it doesn't mesh, can throw him back with his old linemate Domi and bring Willy up.
The idea with 3rd line Willy is similar to how Pens spread Crosby - Malkin - Kessel across 3 lines in their cup runs - I think the Leafs have good enough players in the supporting cast to be able to pull this off, with each of AM, MM, and WN driving their own line. Ice time would only come down a little for everyone (which I think is a pro over a long playoff run), and they'd still run all the special teams, any time you shorten the bench, etc. Also really like giving Nylander two chippier, high-compete guys on his line to keep him buzzing. Just adds more offensive layers. I'd do that whether we get Kane or not, can throw Robertson in that space or make one more trade for someone like Duclair or etc.
4th line - speedy, young, chippy, and guys that can really emphasize the D end of the puck. Offense would not at all be this line's priority. Energy and D-zone starts would be this line's focus.
On D, similar idea, all about finding meshing pairs - Rielly/Tanev is clear top pair, but after that I think I'd play the other two a similar amount. If you shorten the bench at all I think Brodie/Liljegren is the other pair to deploy, love Lily's game. With Dumba, I think you get the offensive aspect the Leafs wanted in Klingberg, but you also get some other dimensions - he'll throw hits, not an utter trainwreck liability in his own end, etc.
Sub in scenarios:
- If anyone top 9 is hurt, Robertson in, followed by Holmberg. If it's a top 9 C that's down, Nylander to C as well
- If anyone 4th line is hurt, Holmberg comes in, followed by McMann.
- If we need a fighter for a game for whatever reason, 4th line becomes Greer - Kampf - Reaves
- D hurt - Gio fills in, followed by Timmins, then Lagesson. I'd entertain throwing in Timmins first if it's Dumba so he can run PP2