It's tough to get someone who can do Xs and Os strategy and also the motivational side. Tremblay motivated players, scared them, even, but he didn't understand modern power dynamics in hockey, and I doubt he really got strategy. Most coaches only do one or the other, you have the old school discipline guys, player coaches, system coaches. A few guys, maybe Trotz, are good at most aspects. Most teams just switch between types. Get a systems coach if you're team is getting outcoached, get a disciplinarian if your team is too loose, get a player coach if your team is sick of a disciplinarian.
The habs have had a series of similar coaches, and that is a pretty dumb thing to do, but at least MSL is a change. We'll see if MSL can make the jump to NHL head coaching without doing the legwork in the minors. Tremblay and Carbonneau could have been great if they'd learned the background, we'll see if St Louis can get that knowledge on his own. I hope St Louis has a source of information, books, ex-coaches, personal genius, whatever.