Yeah but it seems like that 25th man is almost always a stiff, and Blanco's success has prompted the Phillies to eschew both the big-hitting corner IF/LF type or the no-hit SS (though Ruf was the former and Paredes and Burris managed to be the latter w/o being primarily shortstops).
If the bench is:
Altherr/Nava OF
Stassi/Blanco IF
Knapp
Then sure, give Stassi the shot. But I suspect Nava and Stassi are competing for the same spot, a corner OF/1B hybrid, and that fifth spot will actually go to Pedro Florimon or Hector Gomez. In that case, why not a catcher? It would be creating more opportunities for Knapp, especially since he's a switch-hitter. And if Blanco does play more OF, well, he's a better hitter than most of last year's OFs, and probably better than Kendrick and Nava too. Assuming he can keep it up.
Mind you, I think there is more going on here, first it was repeatedly reported that the Phillies did not want to pair Rupp with a young catcher, then, especially given the 40-man crunch and failure to keep Ellis, Klentak said he was ready to go with Knapp, now they go and add a second veteran non-roster catcher. They aren't good veteran catchers, offensively, but Ellis looked pretty done too. Maybe Occam's Razor still says they are disposable spring training bodies but it wouldn't surprise me to see one of them on opening day, wherever Knapp may be (Philly, Allentown, another organization). If nothing else Logan Moore seems like a goner.