Although this seems like an even trade on the surface. The Sabres are most likely not interested in Vladar, they would rather start UPL and Levi next season, or sign a vet UFA. Mitts is probably untouchable right now. And the Sabres would not give up a RHD for a LHD right now, no matter who the LHD is.

Calgary declines. The Flames won't want Comrie or Olafsson and don't need a defenseman coming back either.

Edit: On second thought if Calgary trades Tanev (and they should) Jokiharju might be a good replacement for the 3rd pairing (with Weegar and Andersson at RD on the top 2 pairs). Or Calgary could trade Tanev to Buffalo if they need RD and resign Stetcher for the 3rd pairing.

Flames would get more in a trade from the Canucks for Tanev as they badly need someone to play with Hughes

But Comrie would be playing for the Wranglers as 3rd on the depth chart and Olofsson is a goal scorer the Flames will badly need

Even at 50% retention Comrie is way overpaid for an AHL depth player.

Olofsson is a a pending UFA. Calgary's problem right now is they already have too many pending UFAs. Olofssun is a big defensive liability too.