Arabness like Jewishness since the 1st millennium BCE has been spreading through cultural assimilation.

We have Arabized Jews and Judaized Arabs. Judaized Arabs were mentioned by Greek historian Strabo in the late 1st millennium BCE. Herod the Great was a Jewish Arab king.

Still, projecting the Biblical story onto today has some truths to it and applicable lessons but is not the truth. Arabs and Jews today are no more cousins than Indians and Icelandics, though both speak an Indo-European language.