[G Larry]

As long as the kids married "half-siblings" and not full siblings, it should have been less of a problem.

Also, I'm pretty sure God solved that problem in the first centuries after Adam, and again after Noah.

[Brooklyn Attitude]

“As long as the kids married “half-siblings” and not full siblings, it should have been less of a problem.”

Marrying your kids off to nearby tribes is a good way to form alliances as well as avoiding inbreeding.