Many of his works are definitive depictions of various components of excellent composition and are meant consciously to be vehicles for that particular component.
I mean here to say that he painted things for the sake of the composition itself rather than for any other conceivable reason - simply for the joy of consciously knowing the ins and outs of his craft. It is doubtful that he would have admitted this to any contemporary.
There wasn't anyone there to appreciate such things.
I can't stand these types either. They produce nothing yet know everything after you show them. I recall a Basil Rathbone - Sherlock Holmes movie. Dr. Watson (Nigel Bruce) says "Hrumpf ... but that's so simple." To which Sherlock replies (with great irritation),
"It's always simple, Watson ... after I've explained it."
Anyway, Rubens is to art what Euclid is to geometry. He pulled it all together in visually explicit statements of the rules of good composition.
I shall demonstrate this thesis in the following pages.
The source of Rubens compositional forte is undoubtedly Leonardo DaVinci as evidenced by Rubens painting of LDV's unfinished "Battle of Anghiari".