My DD started with a new hitting instructor a few weeks ago a former college player with some accolades. Her swing has become more sound in just a few lessons. However I'm curious the first few lessons she used baseballs for about half the swings and then at this last lessons used just baseballs. Is this a teaching technique or is this just because she teaches at a baseball facility so baseballs are more plentiful. Any upside or downside to baseballs?