Half measures.
If keeping Tavares and promoting Cowan makes you slightly worse than last year when you didn't win shit, then you'll win even less shit next season. So if you arent winning the Cup either way (and, trust me, you aren't) then why go halfway? Get rid of Marner AND Tavares.
Nothing will stop the crash that is coming so stop wasting time and money trying to prevent the unpreventable and just drive it off the cliff and crash it instead of watching it slide slowly down the hill for 3 or 4 years as you try to apply the brakes.