Microanalysis and exemption of a single player (a closer) on a roster kind of misses the point. If the Reds had their roster from 2012 or their roster from 2012 sans Chapman plus Cordero (2011), which roster would win more games? The fact that Cordero only blew one more save than Chapman means that the Reds go 96-66 instead of 97-65 right?
Better players win more games. There isn't a need to move Chapman both because the Reds' rotation is very solid and because their bullpen without Chapman is not.