Not saying that I think the Pens should trade Kessel and not saying that they should accept this trade. However, from my perspective the Pens could/ should target a d-man if trading Kessel. Maybe something like this.
Hjarmallson(31 y/o) + 2nd + B level winger prospect for Kessel + Hunwick
or
Hjarmallson + 5 OA for Kessel and a small +
Personnaly I would prefer Sheary or someone else moved to help the D, but I also believe Oleksiak and Ruhwedal will be better next season and the Pens might not even need to do anything about their D (other than getting rid of Hunwick)
You're on the right track. If Hunwick is included and the Pens are getting the 5OA as a return base for Kessel - that certainly gets a lot of attention from GMJR. Sheary going out for a defensemen is also a consideration this summer.
Honestly right now, without the 5OA and/ or the inclusion of Hunwick's contract -I'm not sure how AZ beats a few other teams who may have interest. The fact Kessel would like to go there helps, but an offer of mid-6, average defense, or prospects likely gets beaten pretty handily by the likes of St Louis, Buffalo, LA, EDM, Vegas, or anyone else who could use speed and/or scoring in their lineup.
Personally, I'd like to see the Coyotes do better - AZ or St Louis are my biased destinations for Kessel if he's to leave us...but value is often overlooked here. Kessel is a guy who demands that little extra push to acquire, as the Pens likely get 3-4 of the same offer for him.