I think it's easy to overthink. RC+
Realmuto 111, 117, 126, 101 - but he's on a ten game hitting streak.
Hoskins 159, 129, 142
Harper, 111, 135, 155, 115
Segura 126, 113, 111, 98 [BABIP .291, career .317]
Hernandez 107, 112, 100, 98 [BB% 6.2, career 10.1]
Franco 92, 76, 105, 81 [BABIP .227, career .258]
Other than Realmuto, I don't see any "coaching" impact.
Segura and Franco have BABIP well below their career average.
I think Harper's problem is Harper, his swing is too long b/c he's in love with the 450 foot HR, like a pitcher in love with his FB, he's probably uncoachable until he accepts that 380 foot HRs count as much, shortens his stroke, keeps his hands back and uses the whole field.
Interesting listening to Howard admit that the problem with the achilles was him trying to compensate for a loss of power by trying to pull everything when his success came from aiming at the sign in left center field. He was trapped by his identity as a power hitter and refused to adjust. I see the same issue with Harper.