Forgive me as this will get long. Trying to gather my thoughts on all this and it being 100000 degrees outside today makes it a good time. A core thing to keep in mind here is that this isn't fantasy hockey. This is about finding line combos that become greater than the sum of their parts with complementary skill sets.
1) Do you keep 63/37/88 together?
Right now Pastrnak is not a great puck control player. Most of his (5 on 5) goals are coming off the rush or off of one timers where someone else is doing the puck protecting and the cycling in the offensive zone.
This is not a shot at Pasta. He is one of the best young wingers in the game. As Pasta gets more size, he should be able to improve that part of his game, but as it stands now, being paired with 63/37 allows him to get carried a bit when the Bruins have controlled possession in the offensive zone at 5 on 5. Marchand, in particular, really makes that line work. He has years of working the Bergeron on the cycle, is great at seeing lanes to pass to Bergy or Pasta, and on the rush he and Pasta are deadly.
Removing Pastrnak from 63/37 would not only hurt his former line mates, but we now have to find line mates for Pasta that can still 1) do most of the possession work in the offensive zone, 2) have the IQ to get Pasta the puck, 3) can keep up with Pasta on the rush.
If you move Pasta down to play with Krejci, you have an issue with #1. Krejci has always been at his best when he has guys with size that can provide Krejci with time and space, can cycle, and can take Krejci's passes and put them in the back of the net. Krejci does NOT need exactly those players, Krejci+Pasta have connected on some nice one timers, but for both Krejci and Pasta to be at their best, the need someone with size that can help them with possession in the offensive zone.
DeBrusk currently is not that guy. Like with Pasta, as he physically matures that part of his game can grow, but as it stands DeBrusk is someone who wants someone to get the puck on his stick and let him slash to the net with quickness and finish. A DeBrusk/Krejci/Pasta line is a line with talent that will score goals, but won't possess the puck enough to keep the other team from scoring their fair share as well.
The reason why Cehlarik worked so well with Krejci and Pasta is he can absolutely take care of puck possession and make nice little passes and plays. Cehlarik is able to use his size and IQ in the offensive zone to help both Krejci and Pasta play their best games. The problem is that Cehlarik just isn't a great skater and between Cehlarik and Krejci you have effectively taken away Pastrnak's wheels 10 year early. Add to that, that while 46+88 have looked their best together while playing with Cehlarik, its not like Cehlarik himself has been able to act as more than a glue guy and actually put the puck in the net. If you are going to break up 63 and 88... the Krejci line better be scoring like a first line.
Honestly, the best person to play with Krejci and Pasta is a left handed version of Charlie Coyle that has a little more willingness to shoot the puck. Or a version of Sean Kuraly with some offensive IQ. Or a Cehlarik with speed. Or a DeBrusk that can slow down and protect the puck and create space. None of those players right now are the right player.
While in an ideal world you do spread the talent across the lineup, unless they get help from outside the organization, or unless Cehlarik makes a jump, you are breaking up a great 1st line (with no clear answer for RW in place) and you are putting together a 2nd line that don't cover their weaknesses well.
TLDR is that to break up 63/37/88, you need to get a LW that can cover 1, 2 and 3 above and that guy doesn't look to be on the roster.
2) If Pastrnak stays on the 1st line, who plays RW with Krejci?
First, I think that unless you bring in another LW from outside the organization, DeBrusk is your #2 LW. You can make the arguments about Kessel being on the 3rd line in Pittsburgh all you want, but the Bruins are short top 6 forward talent before you move DeBrusk down a line. The Bruins don't have Crosby and Malkin.
As outlined above, DeBrusk isn't the perfect linemate for Krejci. While Krejci is one of the best passers in the league, DeBrusk doesn't really do much to give him time and space to operate and nor does DeBrusk slow his game down that great. While DeBrusk can certainly be part of a Krejci line (Krejci does a very good job of getting the puck on DeBrusk's stick when DeBrusk has a path to the net) they need someone that can bridge the gap between them. Marchand makes Bergeron and Pasta work. The Krejci line needs someone that make DeBrusk and Krejci work. DeBrusk needs someone who can keep up on the rush + someone that can help with the possession game and Krejci needs another person who can help with creating time and space and working the cycle.
Coyle could be that guy. Someone who can control and puck and make space and give the skill guys room to operate. Of course, you then really mess up your 3rd line, and a lot of folks would grow to not like Coyle on a line with Krejci as Coyle is a guy who just doesn't shoot the puck enough.
Kuhlman has enough speed to keep up with DeBrusk, is tenacious on the forecheck and isn't afraid to shoot. He checks a lot of boxes in what you are looking for in completing that line. But, does he have top 6 talent? Seems like a big ask.
Senyshyn is along the same lines. Big and fast, but has his Providence training in "bottom 6 skills" put him in a position to use his natural talent and a rounded out game as a top 6 wing on a Cup contender? Seems like a big ask.
Back when Seguin was dealt, I would have thought Ritchie is someone that would have checked all the boxes as a RW for Krejci. Heck... maybe playing with Krejci and DeBrusk he can be physical and score 15-20 goals. Seems like a big ask.
Bjork probably fits well with DeBrusk, but not sure if Bjork+DeBrusk work great with Krejci. Those two wingers really need a different kind of center. Which brings us to the crux of the matter...
The Bruins are trying to build a team around skill on the wing and responsible possession guys up the middle and Krejci is out of that mold... but he is still a low end #1 to high end #2 C... and those don't grow on trees. So while Boston doesn't seem to be interested in getting another Oates, Janney, Savard, Allison, Barzal or Krejci pass first offensively focused skill guy at C, they have one now.
You can find a "RW for Krejci"... one that has size and puck control skills, but he has to be someone that is good enough to be in that role in a post-Krejci world. Finding some modern day Lucic or Horton that can skate and be worth the cost after Krejci is gone... but that you can fit under the cap and are able to acquire seems like an impossible list. Mark Stone certainly checked a lot of boxes, but the Bruins really could put together a package to match Vegas realistically, nor do they have the cap space right now. And, more importantly, at what point to you decide that "finding a center for DeBrusk and Pasta" starts making more sense than finding a winger for Krejci?
3) Who fits with Coyle and Heinen?
Speed. Senyshyn, Bjork, Kuhlman. All those guys fit the bill. Not worried.
So I guess after all that you are left with a few options.
1) Stay the course
Let Kuhlman, Senyshyn, Ritchie and Bjork fight over the two middle 6 RW spots and go deadline shopping again for a rental. Maybe Studnicka or Frederic force Coyle up to #2RW.
This seems most likely. I feel very confident in one of those guys sticking on the 3rd line and like the chemistry potential.
Marchand Bergeron Pastrnak
DeBrusk Krejci Kuhlman/Senyshyn/Ritchie
Heinen Coyle Kuhlman/Senyshyn/Bjork
Frolik, Toffoli, Hoffman, etc become names we talk about in the spring to play RW with Krejci.
This is actually the most simple plan and the one that makes the most sense. But it's not very fun.
2) Give Cehlarik a shot
Marchand Bergeron Heinen
Cehlarik Krejci Pastrnak
DeBrusk Coyle Kuhlman/Senyshyn/Bjork
I like 63/37/43 as a two way line. A lot. But, it only works if the Krejci line can be a real #1 line offensively. Cehlarik will have had to had some kind of offseason to be a REAL top 6 player. Love the third line, but I love the third line with Heinen, too.
3) Go get someone signed long term at RW
Someone that can bridge Krejci+DeBrusk and keep the first line as is.
This has been the desired path for a long time, but I think it might be too late to find a guy that will work with DeBrusk and Krejci and also DeBrusk and Krejci's replacement we hope is Studnicka but don't know. I just don't know who this guy is. And I don't know how you afford his salary. And I don't know how you trade for him.
4) Go get a LW that can bridge Krejci+Pasta
And move DeBrusk to 3rd line.
This honestly would be more of a move planning for the post-Krejci world. A LW that can bridge between Krejci+Pasta likely has the skill set to be there when Studnicka or Coyle or whomever is going to be there. Kreider and Hall are the most obvious names. Names that would require moving on from Krejci after the season and would make DeBrusk a "luxury" on the 3rd line. This would be the most drastic move.
