That link doesn't work for me. Sumerian is a possibility for Noah's family, but we're awfully close to wildly guessing here. The Sumerians were the ones who pretty much invented astrology as we know it. And Abraham came from there (from Ur, the second city after Sumer in Mesopotamia). As you say, Enoch seems to be nothing like that school of thought. His astronomy (if it's an original part of the book) strikes me as Greek.
Indeed, Enoch's book on astronomy doesn't have the Sumerian characteristics at all. On the other hand, Abraham who came out of Ur was 12 generations after Enoch.
By the way, the only parts of Enoch's book on astronomy that I have found which are paralleled by ancient Greek philosophy are the reflection of the sun off the moon and orbits. The Greek orbit philosophy was a minority view until Ptolemy at 150 B.C. which would be too recent for Enoch, which was copied in 186 B.C.
I haven't found any source in ancient Greece, Babylon, Assyria, etc. for the other observations. And I am aggressively looking for one.