“Most archaeologists and historians agree that “palestinians,” who are Arabs, originated from Arabia.”
No they don’t. They certainly do not.
There is zero evidence of any mass movement of population from the Arabian peninsula to the Levant. As is the case in most similar situations, we are talking about a small number of male settlers who spread their language and culture to an existing population, not population replacement by the invaders. The latter is in fact very rare. You only have to look at an average Gulf Arab and compare him or her to a typical Levantine Arab to see that they clearly have different origins. Arab is a linguistic and cultural label, not a genetic one.
Even the early Zionists – among them one David Gruen (clearly indigenous to the Middle East with a name like that, eh?) readily acknowledged not only that the Palestinians were native to the region, but that they were very likely the descendants of Biblical era Jews. The absurd notion that European and Middle Eastern Jews were one ‘people’ who were all descended from the Levant came along later.