I don't necessarily disagree with you, but I'm just looking at it through the lens of how the front office seems to want to run it. The depth issue is as much of a idealogical issue as a cap issue IMO. They place way too much importance on physical play. They could have given some games this year to guys that can actually play hockey at the expense of Kolesar/Reaves, but they chose not to. If you could swing Eichel for say Marchessault/Hague/Glass/2 1sts/any prospect not named Krebs. The Eichel injury is concerning enough I'd have a hard time doing Tuch and Krebs. Find a way to move Reaves and a goalie and you could actually have 3 potent scoring lines with cap flexibility now and in the future.
Krebs-Eichel-Tuch
Pacioretty-Stephenson-Stone
Smith-Karlsson-Dugan/cheap UFA
I don't see a way we keep both Krebs and Tuch in an Eichel deal. They would certainly demand one.
I could see Marchessault, Krebs, Hague, 1st, 2nd being an offer. They don't have a need for Marchessault right now but if they retain 1 million on him I'm sure they pick up another 1st and more from a contender looking to add a 30 goal, 60 point winger at 4M for three seasons who would still be only 33 at the end of it.
That would be right near the four 1st round asset ask.
1st=1st
Krebs=1st
Marchessault via a trade=1st, maybe more
Hague and a 2nd=1st
We could still roll three lines but Glass/Dugan would have to be the two young players. I think it would be fine, Glass works on his skating in the offseason and comes back with more confidence. Then we make sure to play him, Dugan and Stephenson on different lines so they have enough support from veteran top six caliber linemates to put them in the best position to succeed.
The fourth line of Carrier-Roy-Kolesar even looks more solid as a threat with Roy on it and gives another player capable of playing up in the top nine.