The second account is merely a more detailed recounting of a section of the simpler first story. It is a common Near Eastern story telling technique found in other Near Eastern Epics. Here is a citation from a source I used in a paper on Genesis. “Comparative studies show that the telling of human origins in doublet is a feature observed in Sumerian and Babylonian stories. In Enki and Ninmah (2000 BC) the first account of human life is a general one, with creation by nipping off clay, and the second covers the same ground in more detail. Babylonian Atrahasis has the first creation account from the remains of the slain deity mixed with clay, and the second elaborates, showing that humans were first created in seven pairs by clipping off clay. In both cases the former is general and the second is specific.” Kenneth Matthews. 1996. Genesis 1-11:26 Broadman and Holman Publishers pg29