my guess

This does nothing for Calgary.

so does letting tanev walk in 12 months. not gonna get much else for him. garland is a player with term who an be flipped in a year or 2 and rathbone is a nice young dman

Why don't the Canucks just flip Garland then? Making one teams bad contract another teams problem isn't usually a good basis for a deal. Garland is undersized, getting paid 5M to produce at the same rate Dillon Dube is producing for less than half the cap hit. Rathbone is 24, 177 pounds and got less games than Briesbois, Burroughs, Wolanin, Juulsen.. That's not a nice young D man, that's an AHL tweener. There is a SIGNIFICANTLY better deal out there for Tanev if they go that route.

Tanev can be traded at the deadline for a 1st, happens every year (if he's healthy)
Literally no reason for the Flames to take a camp dump from a division rival, Garland's contract is atrocious.
Rathbone is a failed prospect, he's got no value as every team has a handful of these guys.

tanev for a 1st most definetly doesnt happen every year lol. and garlands contract is far from atrocious. calgary going to need to aquire players with term unless they fully blow it up