No claim needed. Egypt held it for a long time, and some cultural assimilation is to be expected.
(May I lapse in Archaeologist-Speak for a moment?) Finkelstein and Silverman were probably right as far as no external conquest of the Canaanites took place. The pottery stayed consistent, and the walk between it and Egypt was short enough that the supposedly-long treks in the Bible took only a few weeks. Records in Egypt mentioned such tribes dropping by for a year or two. There is no reason to imagine any other treks than the occasional, "We'll give you camels if you give us wheat," deals.
People who approach Archaeology from a "It's all scientific!" and not a "For thousands of years people have tried to cut the best deal," standpoint have come out as morons. Modern teaching methods may teach otherwise, but I have had decades of fun [del]showing how they are morons[/del] pointing out their fallacies.