Aren't there 2 creation myths in the bibl anyway?
Sort of, but there's a lot of overlap.
It could be explained by two different people writing down the differently mangled story they'd heard passed down by different people. Imagine, for example, two people from different villages in late medieval England writing down a story about King Arthur that had been passed down from generation to generation independently in each village. You'd expect differences between the two versions (and between either version and the original story).