Multiple good points here, thx for sharing your thoughts.
First off though -- Re: Nylander, I don't really blame him at all. He's making ~7m, all of AM, Mitch, JT are at 11 or above ie 50% higher than Willie makes. And sure, Nylander's not a center, he's not the face of the franchise nor has he scored 60 goals. But like... 50% difference in pay? Keep in mind his offensive totals last year were about the same as Auston's -- actually slightly higher though AM34 missed a few games. And idk about you but if I'm doing about the same level of work as a few of my co-workers, yet they're all making 50% more than me... absolutely I'd be asking for a raise to bring our salaries more in line. So no, I don't blame Willie at all -- sure I think most would agree that AM34 should be paid more than Willie, but that difference shouldn't even be close to 50%.
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Everything else you said seems on point. I do think that there were more than a few opportunities to fix the D around the edges (someone like Gavrikov this past year for example), but yeah, first time that someone like EK is available. But, how do you clear the cap space? Quick look at capfriendly shows it's not that easy, all of your big contracts have at least some sort of no trade protection. So you would basically have to re-tool your entire roster to make that happen. In other words, taking a gamble on a high cap-hit EK would take major surgery.
And Tre is one of the only GMs who have done something like this, and recently. And at the time everyone thought he got an absolutely stunning return for Matty Tk. Great point.
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Really curious to see what happens here, not only this year but going fwd. I think most teams with a young, elite core should basically keep their guys together for a while and see if / when they win the cup, as we've seen with teams like Tampa, Colorado, WSH it can take quite a long time. But in the cap era, I can't think of another team's young core who are this focused on getting paid, which obvi makes it much harder for their GM to build a team around them. As a neutral, very curious to see what ends up happening here not only now but over the next decade or so