^ Mostly this. I do wonder why ClockTower insists on asking questions that he already knows the FET answer to?
There are two facts that are important. The first is that Saturn in the last planet anyway. Neptune, Uranus, Pluto if you call it a planet, doesn't matter; they are all made up. I know this to be a fact because there are only 7 days in a week. It is confirmed by most European languages.
Sunday Sun day
Monday Moon day
Tuesday Mars day Mardi in French Martes in Spanish
Wednesday Mercury day Mercredi in French Miércoles in Spanish
Thursday Jupiter day Jeudi in French Jueves in Spanish
Friday Venus day Vendredi in French Viernes in Spanish
Saturday Saturn day
English has a few Bastardisations because of our German/Norse language roots (Frisian) so instead of calling Mercury, Mercury we have Wednesday from Wodin. Thursday from Thor instead of Jupiter. Same God/planet.
Conclusion: There are the sun + moon + 5 planets. Otherwise there would be more days in the week. There is no Neptune day or Uranus day. It shows they just added those at a time when they wanted to get people excited about RET, gifting them new and magical fantasy planets.
The second fact is that retrograde motion has been explained by the works of Ptolemy as I have referenced
here and
here for example and Tom Bishop has referenced
here and
here.
You will notice is diagrams like this below from Ptolemy he doesn't add any of the made up planets either.