I've noticed that leftists tend to dismiss Joan Peters' book by simply claiming, "it's been disproven" but never explaining exactly how.
When pressed, they will insist that "Norman Finklestein" or "Noam Chomsky" allegedly "disproved" Joan's book, but never give any citations. It is enough for them to invoke the names of those two anti-Semitic nutcakes as some kind of "proof."
Amen , Sisterb'shem Y'shua