I don't think they have what it takes to play a mature game yet. Gifted offensively but very soft and very porous defensively. Florida and Vegas both designed their teams for Gallant upon his arrival. I think the Rangers are going to be very active on the trade front to accommodate Gallant
Other than -like I said- Strome, I'm not sure who you would look at on the roster and say "oh that's never gonna work."
Kreider and Zibanejad were both regarded as high-motor, 200 foot players before last year. Buchnevich is nasty and plays good defense. Panarin played for Torts and they got along fine. Lafreniere has been highly touted for his compete level. Kakko was asked to focus on his defense this year and turned in elite defensive metrics (and got benched anyway, that's part of the problem).
They were guilty of leaning on East-West plays with the puck a lot but that's because 1) players lean on their talent when they're playing with no structure and 2) Quinn's idea of accountably was "are you 23 or older?"