Joe Rogan doesn't interview people. He might have stuff that he wants to bring up, but most of the conversation is organic which is part of the appeal I think.
> If someone is an expert in their field or has a depth of experience, I'd prefer him to be challenged by someone with a similar level of expertise.
Preparing for an interview will give you some superficial understanding, which will probably fall apart during the interview, unless the interviewer is very intelligent/curious (Sean Carroll's Mindscape and Newtons Apple comes to mind).
Another alternative would be to have people on both sides present, but I've never seen that work out. The discussion you get with hostility is nowhere near the discussion you get with curiosity.