His floor is 12 considering the worst teams in the league would be happy to give him that, maybe even 13-14 seeing as they'd have the money and the cap is going up.
From a Toronto perspective, it's 100% down to how he does in the playoffs. At some point you have to try something different if it's clearly not working like we see in Toronto.
All the 4 of the core are the same player, softer skill guys who struggle in the playoff. Clearly you need a mix because even though certain players are more built for playoff Hockey and all it entails, you need the skill guys to get you a good seeding, a good matchup and actually make those skill plays which the tougher players can't make.
Barkov and Tkachuk are a good highlight of that, both of them did nothing in the playoffs alone and neither of them were good enough to carry a team anywhere, until they were paired together. A perfect match, the skill scrappy heart and soul guy with the guy who has otherworldly skill and is amazing defensively.
In Toronto the 4 are too similar for it to work/be cohesive, this is probably their last shot