Not to derail much here but Vasi completely stole a few games for TB, including a few do-or-die game 7s in which he was untouchable. TB very likely does not have any of their Cup rings without him.
As for Eastern Conference D-men, maybe we have different opinions on what "dominant" means but by my count the Rangers have Fox, TB have Hedman (not sure if he's still that dominant, haven't seen him this year), Carolina has Slavin, Boston has McAvoy, Pens now have Karlsson, and up and coming teams like Buffalo and Ottawa have locked up future studs in Dahlin, Power & Sanderson.
Unfortunately for the Leafs, even if Willie is moved and/or Tavares comes off the books getting that stud defencemen isn't that easy. If they haven't drafted one, or one doesn't miraculously hit free agency good luck trading for one.
Treliving has a real task ahead of him filling out a Stanley Cup blue line regardless. Brodie and Gio may not be around long, Klingberg could be great but walk next Summer, and that leaves Reilly, McCabe, Liljegren & Timmins.