I think Lou and Babcock will eventually make the Leafs legit again. I can see them building a team that is at least good enough to be a "pretender". We'll see if they can become a true contender. Kind of what they were like when they had Pat Quinn running the organization in the late 90s. He was the last quality hockey guy they had who gave that team any sort of long term success. Then they hired John Ferguson and the fall began.
Lou is a disciplinarian. With no internal leadership core on the team itself, it's paramount that the coach/G.M. are able to establish a highly disciplined atmosphere, and communicate to the players clearly the expectations and responsibilities. They are going to have grow their own leaders as an organization.
They will need their young players like Marner, Nylander and Reilly to become their leadership core. Lou and Babcock are there to help them develop that. Both know what it takes to win, and will garner much respect from the players from the start.
The Leafs are not going to be very good, but they will work hard next season. They are still 3-5 years away from making the playoffs, because their overall organizational depth really really sucks.