IMHO the issue is lack of physicality, and being soft -> YES
But I don't think getting any physical players is going to solve any issues.
Why?
When I look around the league especially the teams that have had success:
Their core guys actually play physical (or dirty sometimes); they are not boy scouts always looking at the refs. They can dish as much as they can take.
examples:
Tampa: Point, Kucherov, Stamkos, Hedman, Sargechev etc.
Avs: mack, Rantanen, Makar, Landy, etc.
Bruins: Bergeron (not dirty but finishes checks and takes hit to make plays); Marchand, Pasta, MacAvoy, Lindholm, etc.
Canes: Aho, Svechnikov, Pesce, Slavin, etc...
etc...
you get the point.
For the Leafs I only see Matthews mixing it a bit; everyone else plays like boyscouts (marner, nylnader, tavares). Its gotta come from within the core; core has gotta get more physical; getting someone else is not gonna help IMO
Also, opposition has way to easy of a time when they stand in front of Leafs goalies; when leafs do that they get punished/boxed out. In the playoffs thats also gonna make the difference