FP, IMO there needs to be balance within the frontal/sagittal plane which will allow the body to be dynamically balanced through out the sequence. IOW's the un-tipping element needs to happen within the sagittal plane while moving forward in space.. This will allow the sitting action to be dynamic.
I agree with the balance comments. Failure to maintain balance in the frontal/sagittal plane results in a hitter laying on the ground I guess I am looking at the un-tipping element occurring after the sitting action starts. So in a sense, I guess you could say that I am suggesting the balanced sitting action is what allows the un-tipping to occur at the moment you want it to. The un-tipping is what is being delayed. Hopefully you can understand that, because I think I just confused myself...