It has long been accepted that in order to develop power, the batter must have forward body movement during the swing. It was believed that in order to develop the required kinetic energy for the swing, the body needed to move forward 12 to 18 inches. But over time most coaches have had to concede that a hard, aggressive move is not necessary. Today they recommend a short soft stride while still maintaining that a weight shift is essential. Many coaches do not understand there is a clear destination between the body's movements to the launch position as compared to the body mechanics of the actual swing.
Most hitters do stride forward as they prepares to swing.
But once the actual swing is initiated, hand acceleration and body rotation begins, there is no further forward movement of the body. The rate of angular displacement of the bat is derived from torque and rotation energies around a stationary axis. The batter has rotated to the launch position and completed his timing step. The front foot has been firmly planted. Forward motion has flow to a stop and he is ready to initiate the swing.