Fabbri should never be a top line center on any team, at least not until he proves that he can be a center in the NHL. The faceoff percentage is being vastly overstated though. Yes faceoffs matter, but they don't matter nearly as much as kip is making it seem. A 45% center can win a faceoff against a 55% center on any given draw. It's still basically a coin flip. What happens after a faceoff win or loss is what matters much more, and that's where Fabbri would fall short to Larkin, as well as any other 1C in the league.
Larkin was just under a point per game center the season before. The team last season was historically bad. That's not on Larkin. You can't assume a downward trend because of one down season. I guarantee Larkin will outpace his points from this past season, next season. He will also out produce Fabbri while playing against tougher competition every night.
Assuming both are healthy, Fabbri will not play a bigger role on this team next season (or any season) than Larkin. Sorry man, but I really can't believe this is even a discussion, much less a debate.