One of the problems with questioning the accuracy of the Gospels because of conflicts with historical accounts (something I don't mind doing myself, but I'm not selective about which religious doctrines I'm willing to question), is that it leaves open the possibility of questioning the Jewish version of events also, and not just Genesis.

There is no historical documentation for the existence of Moses, or even of the Hebrews having been enslaved in Egypt or of the Exodus. We have no way of historically verifying whether or not the Jewish religion came into being in the way their holy books describe, or if it was entirely invented by people who wanted to start a cult following.

It seems to me that no religion is in any position to question any other religion when it comes to being able to verify their version of events historically.