Disagree. Most scholars date the garden story earlier. The New Oxford Annotated Bible, a study Bible, calls it an earlier, separate story. Coogan and Chapman's textbook dates Genesis 1 probably to the time of the exile in Babylon, in the 500s BC. The textbook also says the date of the priestly writers who wrote Genesis 1 is debated, and some scholars date the garden story much later. The order is well supported, not settled.
Page order and writing order can differ. Coogan and Chapman hold that the priestly writers were also the final editors, which is why their chapter opens the book. The study Bible says the two were probably joined after the exile, as returning exiles rebuilt Jerusalem.
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