Well, FP, all I can say is my DD threw one and she lost maybe 1 MPH. (What "basic physics" is that?)
Here is a video from one of Ernie's girls throwing an over the top drop. Looks like it breaks sharply to me.
YouTube - bucket drill
(By the way, this drill is my only meaningful contribution to pitching.)
What he is telling this girl is to roll her shoulder over. Then for a rise ball it is a different body mechanic. As Bill will tell you all pitches should be thrown with the same mechanics. Rolling the shoulder over does not preclude someone from letting the ball go off the fingers in a peel fashion. I don't think you have thought through what you mean by "over the top" drop.