Personally, I'd be considering taking Knies off of Matthews line. I'd also look at moving Nylander there.
I agree on the Knies bit to improve the Tavares line. Nylander can be really good on Matthews wing once in awhile, but last season it looked like they made each other worse (to the eye) and Berube said as much obliquely. They're really similar in capability and when paired up they set the wrong example for the rest of the lineup.
Matthews and Nylander are very effective together. I wonder if Maccelli might be a complement there.
Maccelli - Matthews - Nylander
While I like this a lot, this would work better under Keefe's system, but soaks up a lot of offense from the depth by piling up all the line drivers together and would likely get iced out in the playoffs. It would be frickin' beautiful off the rush though and good for a couple of highlight goals every night.
Berube preached effortful forechecking to generate offense, which is great for most of the roster; Matthews and Nylander are arguably the two players who have the green light to make on-ice calls to deviate. When paired together, it seemed like they both wanted to be the F3 waiting for Knies + F2 to make something happen, which resulted in Knies losing the puck. F3 is an important role, but I think you'd want L1 to set the standard for the rest to follow (a la Marchand-Bergeron, Barkov-Reinhart, Crosby-Flibit).
The line roles were more clearly defined with Marner on the wing; my beef with that former L1 was that while they did set a style standard in regular season games, they set a bad intensity standard as Matthews-Marner knew they had to play 22+ min and generally started games at a reasonable, rather tentative pace. So many games were slow starts and trailing until the stars kicked into gear with 10 minutes left in the third.
I think we see L3 start most games to set up a heavy forecheck to build first period momentum and make life difficult for the opponents. Roy and Laughton lines will be good for it. Tavares needs some fast smushers but he'll be good for it. Knies and Matthews will be good for it if the other winger is more of a maniac that can let Matthews handle more F3.
