I think if we get much into discussing the overt/withhold/confessional methodology as it applies to mind control that it will take this thread off on a tangent. $cientology is not the only organization to attain mind control results using the technique of getting people to confess crimes. One example of this is in Robert Jay Lifton's Thought Reform and the Psychology of Totalism.
As to Hubbard's intellect, I think it was not staggering, prodigious nor even brobdingnagian. For sure people who have been recognized as intellectual giants and high school graduates have no fear of competition from the likes of Hubbard, at least as long as they stay away from $cientology.
As I understand it Hubbard read very widely. He probably read books that he forbade those involved in $cientology to read. Most likely they were books written to help people from being subjected to mind control techniques, which he then used to gain more and more control over his followers.
lol, I word-cleared the hell out of "brobdingnagian."
I think that the art controlling people was Hubbard's life work, probably before he even realized it himself. Anything that he ever read, learned or heard was later regurgitated and put to use in his quest to manipulate his fellow man. whether it be an actual manual on brainwashing or an old story about some Bolivian general. He was a prodigious writer, but again, his aim and direction was very simple and he wrote from the perspective of the ultimate authority.
His genius was arranging an environment where he was seen as an intellectual, but he never had to answer tough or spontaneous questions.