I don't think swapping any of our forwards 1 for 1 is going to make that huge of a difference.
If you want to guarantee this year doesn't happen again, the path to doing that is simply completely mortgaging the future. Moving some combination of Casey, Holtz, Mercer, upcoming 1sts, and our B tier of prospects to acquire a true #1 Goalie, a minutes eating LHD, a true 2nd/3rd line center that can move Haula down the lineup. Another 2nd/3rd line winger that can push Palat down the lineup as well. Get somebody to retain on someone and then fill the bottom six with new depth. Nail the coaching hire, hope Dougie comes back as his old self, hope Nemec is ready to shoulder a heavy defensive load and Jack recovers fine in the offseason. We have the trade chips and cap space to go out there and fill every hole in the short term.
Not saying that is what I would do, but if Fitz thinks his job is on the line he might be inclined to swing for the fences and figure out restocking the pipeline/fixing the cap implications later.