these numbers dont mean anything one way or the other. pd's are the closest thing to the most meaningful stat here, but you still have to account how many times the dbs were targeted in the first place and all that.
Targets
Sherman 2012 (First season as starter): 87
Revis (last three full year average as starter (08,09,11): 93.3
One of Sherman's greatest strengths is luring the QB to throw the ball into a small but open window so Sherman can have a chance at an interception (see Kolb and Brady) . Even with that he still has a low number of targets
QB Rating:
Sherman 41.1
Revis 44.6
Important to note that Sherman's sample size is much smaller. There still remains the question of consistency which Revis has proven and Sherman has not. It will be interesting to see if Sherman can play at the same level for multiple seasons as Revis has.
Revis is still the better and more proven talent (it's closer than most would admit though), but factoring in age and health I'm taking Sherman if I had to choose one for my franchise. In a single game I would probably choose Revis.