Hronek went for a mid 1st plus a 2nd. I would say that is the most comparable trade that has happened lately.
Hronek is an interesting comparable to bring up for Andersson. But i'd take Andersson pretty easily over Hronek...even knowing what we do
after the trade, with how well he's worked out for Vancouver.
At the time of that Hronek trade, he was looked at as much more of an offensive-skewed 2nd pairing type D. Rasmus Andersson is much closer to a true Top-pairing all around guy. Especially compared to Hronek perception at the time of the trade.
All that said though...
If the Sabres would be happier giving up Cozens for Andersson rather than Mittelstadt, that's the sort of deal that probably makes the Flames actually consider it as well. For Calgary...Cozens >>> Mittelstadt in terms of what they really need.
I'd almost wonder though, if instead of throwing Krebs in there...there isn't a backfill Defenceman that wouldn't make more sense as a small+. Even Jokiharju maybe. He's a true #4/5 tweener and he's small, but if the Flames are losing Tanev and then trading away Andersson as well...they're going to need to backfill a little bit at RHD and Jokiharju would at least provide a little bit of something to bridge the gap. Also really not worth much and not really needed in Buffalo in this sort of deal.
Krebs feels like selling really low on a guy, which is always going to make that "value" complicated to ascertain. And for Calgary...Cozens/Kadri/Backlund has things pretty much sewed up down the middle anyway.