I think he’ll be a third-liner. I could see a line of Coleman - Zajac - Simmonds being very effective. All of those guys can chip in 30-40 points and bring a nice mixture of grit and intensity, plus Coleman & Zajac can cover up Simmonds’ defensive shortcomings.
Top six right now should be Hall, Hischier, Hughes, Palmieri & Bratt with one wing spot open for competition; be it another addition or the internal competition between Boqvist, Zacha, Wood & Anderson. The rest of those guys can form a skilled 4th line that can play sheltered minutes and offer a change of pace on nights where one of the other lines is struggling.
Rooney & Hayden are probably the 13th & 14th forwards, two veteran guys who can play in a pinch and bring another dimension to the table if we need a heavier/grindier lineup against certain teams.
McLeod, Bastian and others (maybe even Anderson) should be in Bingo unless they legitimately earn themselves a spot. There’s no point them being extras in the NHL when we have guys like Rooney & Hayden to fill that role and play 30-40 games each throughout the season.