I just started listening to this podcast. He seems to know a lot and is interesting to listen to. But I can't tell if he's stating facts or opinions. Are there any history experts here that can vouch for the podcast?
hi! not discouraging other responses, but there have been several posts on Carlin (as well as countless questions arising from the episodes).
As good a place to start as any, FAQ section Historians' views of Dan Carlin's "Hardcore History"
A bit of a tl;dr from /u/400-Rabbits in Opinions on Dan Carlin
Out of interest, a thread featuring /u/DanCarlin himself Dan Carlin claims that "You could take the roman army at it's height in history and send it 1000 years forward, drop it back in europe [...] and have it mop the floor with the greatest armies of the early middle ages relatively easily". How true can we assume this is ?