Echoing BigRon, my picks will not have changed much over the past couple of decades of great hitting. The eras vary too widely to offer comparison which I trust. However, any statistical comparison must weight the effect of defense quite heavily.
For example, we will never know to what extent Bench carried the younger members of his pitching staff as opposed to the extent the rest of the defensive team carried the staff. The only name pitcher prior to Tom Seaver (1977) which Bench caught in the starting rotation was Don Gullett, and Gullett was an oft-injured pitcher to say the least.
Times have changed more than any of us realize, IMO, including myself. The running game was a very big part of offense after Maury Wills and prior to Canseco/McGwire and the A's of the late 1980s. Bench was perfectly timed for this trend, because he had monstrous hands and could pioneer one-handed catching to combat base stealing. Bench was one of the last defensive players who transformed their positions in modern times (along with Ripkin and Sandberg).
So, in summary, my rankings would be (with consideration of segregation's effect on Campanella):
2. Berra (have you reviewed how little he struck out, in consideration of his reputation for a free swinger? Wow!)
4. Ivan Rodriguez
And, I am not sure where I would place Piazza for the same reasons I have supported Bench.
Catfish Hunter, RIP. Mark Fidrych, RIP. Skip Caray, RIP.
A fanatic is someone who can't change his mind and won't change the subject. -- Winston Churchill.
Experience is the hardest teacher. She gives the test first and the lesson later. -- Dan Quisenberry.