The word "create" in Gen 1:1 includes a once-used alternate meaning. In Joshua 17:15, it is used to mean "cut down, or divide." To split. To separate.
Heaven (masculine word); earth (feminine word). Separate, but perhaps made of the same thing.
It echoes.
"Splitting to create order" is the prevalent theme: heaven/earth, light/dark, waters-above/waters-below, water/dry-land.
I think "in the beginning, God split heaven and earth" can be a reasonable additional view of the text.