There was an interesting interview with former Braves' and now Yankees' minor league IF Caleb Durbin during last year's Arizona Fall League. His statistics in his one-plus season in the FCL, Augusta, and Rome were pretty anemic. The Braves traded him to the Yankees along with Indigo Diaz for Lucas Luetge. Durbin was tearing up the AFL and during the interview, he was asked how his hitting turnaround started. He didn't throw the Braves' hitting instrution under the bus or elaborate what they taught, but he did compliment the Yankees' instructors with teaching him how to swing hard in the zone.
Durbin as done well and even with the change in approach his walk-rate is > 10% and his K-rate is slightly below 10%. I don't know if this makes Durbin a prospect or not, but I did find it interesting that his stats have just gotten so much better with the Yankees' A, AA, and AAA teams. Part of that may be just him becoming more acclimated with the pro game, but I have to believe instruction has something to do with it.
When I look at the astronomical K-rates of a lot of the "highly regarded when signed" guys (especially the international signings), I don't know if that can be laid at the feet of the scouting staff or the instructional staff. I'm not calling Seitzer a scapegoat, but with his exit maybe it's time they look at hitting instruction bottom-to-top. Seitzer could only do so much with guys who may have been ill-taught during their minor league careers.