Their scuffle in game 3 (?) made me wonder this.
Both are big parts of a successful hockey team. Both have skill, grit, athleticism, and an edge.
Personally, I would want Marchand. He seems to have more refined skill than Shaw does. Although Shaw is an all-around good player offensively, Marchand seems to have a better shot, is a better passer, skates faster, and has more discipline. Shaw still seems a bit too immature.