When you wrote in your second to last paragraph that " Many of today's competitors don't quite dance it exactly according to the book ". Maybe that is the reason that there are never any overhead shots of the dancers. Because they often use different alignments to those in the Technique Books, and don't want to throw a spanner into the works. I know in my book if I followed it to the letter my partner and I would be trying to stand in the same spot at the same time. Alex Moore did excuse himself by adding that the book should not be followed in a Parrot like fashion.