I see it as a mutual research group, not a group attempting to find bullshit in other members.
My understanding is: Someone asks: Is this bullshit? Usually it’s Ian but it could be anybody.
Then everybody in response gives some reasons why or why not bullshit. Some are better at it than others as with all things.
I’ve never seen anybody else turn on a fellow member of the group. That just makes it a standard debate group.