Maybe, but you would agree that OPB and slugging is the correct way? Your position is that it is correct but it may or may not yield a significant results is baffling. If it just leads to ONE extra win per season why would you not do it?
If you can generate one extra win by optimizing the lineup, and if you can generate one extra win by always bunting in the correct scenarios (and not bunting when you shouldn't) as a coach you are actually making a difference.
The converse is going by your gut and eyeball test...that's just ego in my opinion. You shouldn't coach by statistics and analytics only, but you need to be informed.
If I set my lineup optimally and the other coach does not now I have a small advantage in that game. If the other coach steals when they shouldn't I have another small advantage there. Add up enough of those advantages in one game and now we are talking about meaningful differences that will affect the outcome of that game.
As you pointed out it doesn't guarantee victory every game but if you do it enough times over enough games you will win more games.
I agree with you, but I also agree with JAD that the sample sizes are just too small in many cases. You'd have to regress the data so much that I'm not sure just how much more useful it is than the eye test (since I'm pretty sure nobody here has exit velocity on balls in play or anything like that).
That said, K rate and BB rate normalizes a lot faster than everything else. Assuming reasonable, consistent competition, I don't think it would take too many games to be able to figure out who on the team struggles with making contact/plate discipline/pitch recognition and who doesn't. That's not everything, but it's something.