I agree that the timetables cannot be rectified, but at the very minimum, it could be taken as a sign that the Jaredites ~2500 BC or the Nephites/Lamanites ~600 BC, COULD possibly have made the trip.
This is less a pure religious argument as it is disputing the fact that ALL migrants came from the straights, as evidence currently only proves for North America. There is no trail south however.
If the timetable in the article is assumed to be correct, am I to understand that there may have already been people in the region when both groups arrived? Does the Book of Mormon mention anyone, or is that unclear?
PS: this
wiki is a veritable wealth of information on the topic of Mormon archeology.