Montreal's been looking for a centre since Jacques Lemaire - you add an elite superstar centre if you're lucky to have the chance to. And the $11MM is less than what the market would bear - given what SJ was speculated to be offering.
This whole narrative of the Leafs not needing another centre is so stupid. And Gord Miller saying how Kadri or JVR had almost as many goals as Tavares over the past year/two years, whatever - is utterly ridiculous.
ELITE players are rare, those who make players around them better and more dangerous. Those who don't need a defensive breakdown or a mistake to create a scoring chance, those who can play against TOP players and still produce.
All things being equal, if there was an elite defenseman available for the same money (Karlsson) then maybe it makes more sense, but that's not a lock either. Pitts won a few cups with two elite centres and an arguably worse defense than what the Leafs have today.
Adding more scoring doesn't mean the defense is worse by comparison - unless you're only comparing the relative strengths of your offense vs. your defense, which is stupid. Adding more scoring only makes it easier on the defense, it lessens the burden on them.
So yesterday, the story is how Marner was superb, how the PP and PK won the game, not how many turnovers in the neutral zone, giveaways in their own end, coverage in front cost the Leafs the game. The result is a win and a celebration of offense rather than a loss and further question marks on the defense. Either way, adding an elite/rare superstar brings ZERO negatives to this situation - sorry Gord Miller