I think Marner the player is really good, for whatever it's worth. Like really, really good. Top 3 Leaf drafted by the team in terms of straight up talent and production.
He's just not what this team needs, unfortunately. I don't think the Leafs should be spending 13+M on a perimeter playmaking winger that needs to be hitched to our 1C at all times, and certainly not one that has a negotiation team that specializes in hissy fits and public grousing.
Is there a world where I would think this could work? If the Leafs lose Marner the $11M forward, but sign him as Marner the right-shot defenseman at 9.5-10M, I would consider that a huge win (no joke). Or if he just said, I love Toronto, I want to win here, I'm taking the Nylander number (scaled to current cap) and plays like a friggin' rat with a chip on his shoulder the rest of the way, I think a lot of fans would be more than fine with that (transplant Brad Marchand's attitude and demeanor into Marner's skillset).