Mark Fine,
Shifting the tee boxes around and significantly altering the yardages conflicts with establishing handicaps from golf course's "rated" yardages. ( blue, white, red, etc.,etc..)
A golf course's overall yardage must remain consistently balanced to assist in the effort to determine handicaps.
Moving a tee marker from 200 to 140 is okay, but overall the course should play to approximately the same yardage.
Slope is fueled by yardage.