We all know Kaner has been great at times in the playoffs and a few times not so great but the team's record (3 SC's in 8 years) erases pretty much any of the inconsistencies in his performances over the years.
Bottom line is Hawks need help on defense first and foremost. Re-acquiring Panarin will put a huge dent in cap space available thus seriously compromise Hawks ability to shore up their main weakness, defense.
If it is entertainment one values, then Panarin would provide that. He and Kane can work the perimeter and play globetrotter-like hockey with the best of them.