Hersh's big scoops were all corroborated by other news organizations. None of these four have been.
The last one in particular is deeply embarassing and shows the Vox blogger has little grasp of history.
The burden of proof is on HIM. It isn't up for us to debunk what he's saying (though I'm sure many can), he has to prove it, and he hasn't. No single corroboration from other big sources? Seems odd.