This is all fact, Roy?
Conclusively and indisputably?
Indisputable? Of course not.
However the evidence from extant sources and given what we do know about how Genesis was written, it appears likely that's where the names came from.
In the view of some experts, the Biblical Adam most probably comes in part from Alulim (king of Eridu), the first king in the Sumerian King List. He ruled for 28,800 years. We do know in regards to 'Adam' that geneticists have dismissed the notion of a first couple from which all humanity is subsequently descended.
The Sumerian tale of Emesh and Enten reflects the later story found in the Bible of Cain and Abel.
The 11th tablet of the Epic of Gilgamesh contains the Utnapishtim flood myth and has a number of parallels to the Noah flood myth of Genesis 6–9.
Enmunderana appears to be the forerunner of the Biblical Enoch. In Enoch's case, both Enoch and Enmunderana are the seventh name in a list of patriarchs with long lifespans. Enmendurana is associated with Sippar (which was associated with sun worship) while Enoch's lifespan in the Bible is 365 years which is parallel to the number of days in a solar year.
Anyway I look forward to your alternative explanation for the origins of the genealogies found in Genesis. Not surprising that older material was used since Genesis appears to have been written about the time of the Babylonian exile when the Mesopotamian source material would have been easy to access.