"Now what is said here of Jupiter is to be understood of Saturn and Mars also. In Saturn these retrogressions are somewhat more frequent than in Jupiter, because its motion is slower than Jupiter's, so that the Earth overtakes it in a shorter time. In Mars they are rarer, its motion being faster than that of Jupiter, so that the Earth spends more time in catching up with it. Next, as to Venus and Mercury, whose circles are included within that of the Earth, stoppings and retrograde motions appear in them also, due not to any motion that really exists in them, but to the annual motion of the Earth. This is acutely demonstrated by Copernicus . . ." Galileo 1632, Dialogue Concerning the Two Chief World Systems


These men would have understood what was needed to partition direct/retrogrades by the faster or slower, the greater or small circumference and the many other different facets that account for our motion and those of the other planets around the Sun.

https://www.youtube.com/watch?v=FcrBAuLBXag

Either directly or using indirect analogies like Jupiter's satellites, the direct/retrograde motion of Venus is a function of a smaller circumference and a faster moving planet. The great unused proof for the Earth's orbital motion around the Sun as the stars transition from an evening to morning appearance with the Sun as a central reference completes a work that was started 500 years ago.

It is great that people will someday enjoy the full story and that is all that matters.