So he has reinvented Stan Musial's swing. If there was a gif posted of some HS kid swinging like Stan Musial most gurus /instructors would have a field day tearing apart his swing. There are no perfect mechanics and there is more than one way to get it done.
What I do like about what he is teaching is when he says if you connect the lead arm and swing the rest of the stuff (core) will take care of itself. I think the lead arm should be connected, but at closer to a 90 degree angle to the tilted torso, not draped diagonally across the torso.
Throwing frisbees or bats with lead hand for distance will cause an athletic kid to engage core naturally. Also practicing opposite handed has it benefits too.
What I do like about what he is teaching is when he says if you connect the lead arm and swing the rest of the stuff (core) will take care of itself. I think the lead arm should be connected, but at closer to a 90 degree angle to the tilted torso, not draped diagonally across the torso.
Throwing frisbees or bats with lead hand for distance will cause an athletic kid to engage core naturally. Also practicing opposite handed has it benefits too.