Based on what I've read I kind of have a hard time picturing Fiddler halting the march of age very much when it comes to his skating speed and his face off numbers falling, but at a cap hit of just over $1 million for one year, what's the harm?
Beyond that, and maybe more importantly, it's a step toward getting more guys off the starting lineups who clearly aren't NHL starters. Baseball has the WAR (wins above replacement) stat, where people who are around a 2.0 WAR are typically considered to be average players and 0.0 considered to be emergency minor league call up types, and guys in the negative...uh, they suck. I know hockey has begun using WAR, but even without the data I have to imagine that swapping out Gio for Fiddler likely results in a solid WAR improvement from that spot on the 4th line, getting a legitimate NHL talent in that spot over a guy who really shouldn't be starting that often.
Shero going a lot for depth the last couple of days, not a bad idea when you don't want to risk getting caught with your pants down if the big name talents fall off the board soon.