Dubas is trying to play the analytics game of having several high end players that bolsters the team, while having cheap "statistically proven" contracts to fill in the holes. This creates an issue with the fact that all of the Leafs big contracts are offensive studs, with next to nothing on the blueline.
Babcock is trying to make the team he has play to a style that its not capable of, and Dubas hasn't brought in anyone ( while getting rid of the guys who play to Babcocks coaching style) to fit into that system. Coaches don't change styles, players do. Either you have a group of players that are willing to do the work to fit into a system, or you find a coach that is fit for what the players are able to do.