The majority of the Jews in Palestine are not Ashkenazi. As far as my facts, the 40% I got from De Haas who quoted the U.S. Census Bureau. 
Jerusalem was majority Jewish in the 1850s and the Muslims did not form a majority in Palestine until the 12th century. 
The Palestinian Arabs are partially made up of indigenous people. e.g., the Samaritans in Nablus largely converted to Islam. 
But irregardless., my final point was: who's standard sets sovereignty rights based on historical population statistics?: The initial population at Jamestown, Virginia was 105 men and boys and 39 crew-members. From there they took over the entire continental USA. Is that fair based on your projections?
The Jews have also had a continual presence in Palestine, but even if they haven't, they constitute a sovereign people now. They have fought for their tiny country. You and nobody else have any moral authority over them. Canada has no ethnic statistical basis for its existence; it just chooses to exist.