I mean, the stats dont really show that at all...
Turris scored one less goal than Sheahan at even strength last year, and only outscored Sheahan by 6 points at even strength while playing 3 more minutes a night at evens. You can't count Turris' PP production, because to be frank he wont play on our PP.
Turris' most common linemates were Duchene, Granlund, Forsberg, and Arvidsson. Sheahan's were Archibald, Granlund (LOL), PRussel, and Khaira...
Not to mention, the difference in usage between the two players is kind of obscene. Sheahan had a 28.9% offensive zone start percentage, while Turris had a 56.2% offensive zone start percentage.
I'm not convinced at all Turris brings any more than Sheahan. Just look at the numbers dude.