C to 3b mid career transitions have almost invariably failed miserably in baseball history.
Probably human nature to forget the busts....but I can recall several successful c-3b transitions
Sandoval
Torre
Donaldson
Neil Walker was a 3 year minor league C
Brandon Inge....had a long career as utility guy
I'm sure there are more that I cannot recall
and of course i can recall many more C's that moved to other positions....Murphy...Biggio...etc