Most of the so called Palestinians migrated from other countries, just as Yassir Arafat did. He was a native Egyptian, as many in Israel were. Also, most came from modern day Jordan, which was created by the Palestinian mandate. In all honesty, Israel was almost inhabitable until the Jews returned.
they should be a lot taller if they were Canaanite descendants.
Jews were almost exterminated from the Holy Land by Crusaders. Under Muslim rule, Jews trickled back, but it was under the Ottomans that there was significant return. As Jews migrated in, so did Muslims seeking employment and trade with Jews.
By the time the first Godless Zionists showed up, there was swamp-draing, an agricultural school, and Jewish settlements. All such development attracted Muslims for economic opportunity.