I don't want to take anything away from your discovery. I think you really know tennis (you play and coach and not just couch comment).
I just like to point oout that a lot of the things we like to sell as modern have been there for quite some time. this doesn't mean there is no progress but it is not a radical revolution more of a slow evolution of stuff.
regarding the german. the word "grundlinienienzielflächen" means "baseline targets" while "niemandsland" means "no mans land".
Is the "2" (left pic) and "B" (right pic") what you consider the smart targets?