Alex Burrows or Manny Malhotra??
Less jokingly, Malhotra's colleague Dean Chynoweth; he was on Rod Brind'Amour's staff in Carolina and seemed to add some actual structure to that team after they absolutely lacked it under Bill Peters. Truthfully, I only looked him up three days ago after being hella impressed by the Leafs PK off the Clifford major. No idea if he's a good coach, lol.
Gronborg is the hot name these days and there are obvious re-treads like Vigneault and Tortorella available...but none of those names really interest me. Would rather find a highly successful assistant from a highly successful organization under a strong coach.
I've had to Google like 15 times that Andrew Brunette is the Panthers coach post-Quenneville. Literally has not stuck in my mind. But it doesn't matter - they haven't really missed a beat since their HHOF, top-5 coach of all-time was removed. And Brunette stepped in seamlessly.
We're not going to get Quenneville (or maybe we could...) or someone like Darryl Sutter, but when you look at the impact those guys had, combined with the ability for guys like MSL to just step in and... coach - it makes me think the best bet is to look for guys outside the box that could actually have tangible impacts, and not just a Mike Yeo or Dave Tippett, lol.
Finally, I'd also look at adding a guy like Jeff Blashill as an assistant. Obviously just left Detroit, but he was supposed to be the next upcoming superstar coach (in the mold of Cooper, Keefe, and Eakins) at one point, and then late-stage Ken Hollandism hit and he was stuck with a basement dweller for 7 years. He could be a guy that really takes off in a second stint with a fresh new group.