Isn't he the guy who claims that white yeoman farmers make superior soldiers which is why the Spartans, the British Empire, and the US of A were inherently superior to any other military?
EDIT: Yes he is.
He really seems to appeal to people with only a very basic understanding of history, which is probably why Carlin thinks so highly of him.
I think that's unfair - Carlin uses him to describe the physical reality of hoplite fighting, to outline the organization of the ranks, their equipment, the length of battles and so on, and he prefaces any mention of him with the acknowledgement that his viewpoint is hugely controversial. Carlin never makes any point about the West being naturally stronger (morally or in any other way) than the Persian Empire when he talks about Plataea, Marathon or Thermopylae; in fact the opposite, he goes to great lengths to emphasize how something that seems to important to Eurocentric historians - the defeat of the Persian Empire by “plucky” underdog Greeks who save Western civ - is actually a minor inconvenience at the edge of the Persian Empire that is basically unnoticed by nearly everyone within it.
And it's harsh so say he has a basic understanding, I think. First of all, his degree was in history before he became a journalist, which in itself gives him a better understanding than average, and he does cite and quotes pretty extensively through his podcasts. Secondly, he never claimed these podcasts were anything other than pop history. The man’s a storyteller and doesn’t pretend otherwise.