You have to remember that traditional defensive positioning is based on "metrics" too.  I don't think it'd be accurate to say you've abandoned the metric-driven approach if it's situationally dependent.
Ok, I take your point.  I have never really been a student of the game and when it comes to the shift, well sometimes it works and sometimes it don't.  If the formula says that a guy hits left or right against a certain type of pitching and we would 'normally' shift, does that change because a DP is in order and/or we need it real bad?  Are the metrics that advanced?  For me, it is more about sticking with what works, if I used a tactic for 162 games and had decent results, I am not should I would change from what has worked.  Has the shift worked for us this year?