A question about Good Omens (seasons 1 vs 2)

In S1 E1 Crawly (or Crowly) is a fallen angel who took the form of a snake to tempt Eve and Adam to eat a fruit from the Tree of Knowledge. Well, when asked, Crowly says (as Pratchett or Gaiman wrote in the book) he wasn’t fallen as much as vaguely sauntered downward.

In S2E1 Crawly is a non-fallen angel who was the angel who actually created the Earth and heavens and almost forgot to say “Let there be light”.

So, I’m wondering how much time did he have to vaguely saunter downward between those 2 events?

I thought Crowley designed a nebula cluster and was very proud of it. When he found out it was going to be used as essentially wallpaper he was very disappointed. When he learned of the plan to end earth after 6000 years he started questioning God’s ineffable plan, which led to his fall. I don’t see that he was ever the one who created the Earth.

Look, Eisenhower didn’t win the war, it was the GIs following his orders. Crowley just took care of the construction that a Higher Power made the plans for.