Kennedy is an operator. He's actually why I started watching it. He's a UFC fighter and I had heard he was in it so thought I would check it out.Kennedy is probably the least impressive member of the cast. Here, check out their bios, especially the first 3.
http://www.history.com/shows/hunting-hitler/cast
I don't think their backgrounds make any difference to the story but having people with those sort of histories at least lends some credibility to the effort. Of course there are a lot of skilled, intelligent people who believe stupid shit, but at least it's not Billy Bob talking about how he was anally probed by the grays.
It's a decent show I think.