I always find it funny when someone says if you want Karlsson then you must give up Guentzel. If you want Karlsson then you have to give up Letang. Yeah, that's if you are anywhere close to being good. And a minor tweak gets you back on track like with the Avalanche. When in reality what the Senators need is pieces. Accepting Guentzel, Sprong, 1st does nothing for the Senators. They'll pay Guentzel and then trade him when he is fed up with them. What they need is pieces. And then take those pieces and turn them into more pieces. So you end up in a place where Karlsson cleared the cap and you ended up getting you 10 pieces in return. That's how you turn around the Senators.
My deal:
Justin Schultz, Olli Maatta, Tristan Jarry, Daniel Sprong, Teddy Blueger, 2019 1st for Erik Karlsson and Bobby Ryan (1.5m retained)
Note: I'll take Bobby Ryan because I think Crosby can turn him into being a 30 goal scorer.