Hate to say it, but you could add Erik Karlsson to that list as well. And he and Duchene would be in the basement tier together by themselves.. untouchable contracts until they play their way out of these holes they have dug themselves into.
Honestly, the Sens dont get enough credit/receive more hate than they deserve for not only dodging the Duchene and Karlsson contracts, but actually making proper use of them. Two of those contracts on one team would be an absolute decade of desperation for even the wealthiest of teams.
Yes they could have likely signed Stone too if the Sens were committed towards keeping the band together... But even Stone and his 10m/yr cap hit, his recent lackluster playoffs, and his long ass contract that he is likely a retired player by the end of (no legs) - And he might deserve to be on this list too, mayhaps?
Sure, he would be #1 on this list if we put him there today - and likely get a good prospect or half decent bag of small goodies. But Mark Stone is one decent injury and/or down year statistically away from being seen as an overpaid and aging player on a terrible contract. Hes not a great skater at all, and this contract goes until hes 35. Thats a heck of a gamble for any team imo.