I don't think he needs to be creative. He needs to be effective at what he does. I don't think Toews, Bergeron, Getzlaf, or ROR are/were that creative either, but there is a lot of Cups (Playoff series wins) between them. Their wings were the creative ones on the line. The center played the good 2-way game to cover the wings taking chances.
A 30 highlight reel goals count the same on the scoreboard as 30 lawn implement goals. A line that scores 100 goals but gives up 120 goals is less effective than a line that scores 85 goals and gives up 70 goals.
A center that can't play in the d-zone is a wing. A center that can't play in the o-zone is a 4th liner. A center that plays well in both zones is a middle-6er. A center that is high end in both is a 1C.
JEE falls into the 2C, good in the o-zone, very good in the d-zone category.
Hartman falls into the 3C, okay in the d-zone, good in the o-zone category.
Rossi falls into the wing category, good in the o-zone, bad in the d-zone. Nothing wrong with this. The team should play to his strengths.