This concept of shifting defence is what I have thought of for a long time.
This concept I believe relates to the value of walks. Having runners on base has a big impact on the defence not being able to shift the way they want to.
I believe that it is no coincidence that hitters playing on the A's have career years. They always have runners on base. For example, we have seen that having a runner on second takes away the third basement from exaggerated shifting towards the right side of the field as in the case of a lefty power bat at the plate. This creates more room for the lefty power hitter to pull the ball and get a hit. (As a reference, I would love to know David Ortiz's BABIP with respect to the OBP of hitters before him. I believe that he would have significantly high BABIP in the years when the hitters before him have high OBP)
Again, taking Base on balls is a skillset and is more controllable regardless of the ball park factors. Hence, there's an extreme value in the ability to take walks.