Cubs got -1.1 fWAR out of the Fukudome/Colvin collective suckfest. Replace that with DeJesus, have Soriano's BABIP bounceback, and suddenly I think you've gained about 4 WAR in the OF even before Jackson shows up. Even with that, Prince, and Headley "coming close" to replicating Ramirez, the offense still wouldn't be good enough to sustain a hit from losing Garza from an already below average pitching staff. You're also likely getting a significant bump in WAR from the 4 and 5 rotation spots assuming we can avoid trotting the same crapfest out there 2 out of 5 days like we did last year.