Assuming his facts are accurate, is this a problem?

A problem for what? It's not much evidence for a historical-realist-literalist viewpoint, because the usual mythicist or less-literal theories generally believe that the original stories would have gotten started around the time they are set in, and so could be expected to mimick the name distribution of the setting, and keep the mimicking (while warping and evolving in many other ways) until such time as they are compiled by a scribe and set down into a textual form.

Few think that Gospels were made up out of whole cloth in 300 AD and hence having versimiltude (names matching 30s AD) is a surprising feature and evidence against the whole-cloth theory. Generally, both believers and mythicists think some stories and myths and sayings and parables got started in the 30s+ AD and passed down and eventually written down, possibly generations later, at various points like the 90s AD; what they disagree on is how much the oral transmission and disciples affected things and what the origin was.