It depends on the depth of your league. If it's deeper than a 12 team league, a decent closer like Cordero is probably worth more than either Miller or Wolf because of the shortage of saves and the general shakiness of the closer pool this year. If it's an 8 team league and closers can be found on the wire to replace Cordero, it is more of an even deal.
I still would be hesitant to make it though. Mussina is a legitimate #1 fantasy starter, and he will turn it around and should win 18 games in his sleep with that offense. Wolf and Miller are #3 or #4 calibre fantasy starters. If you have little to no rotation depth behind Moose and have decent closers other than Cordero, I can see doing it, but otherwise I wouldn't.