Hubbard was quite good at borrowing little bits of stuff that worked from a wide array of sources. He had a model of how he thought the mind worked and he'd cram them into that framework.
Pound to shape
File to fit
Shim to match
Paint to hide
Wow, that really sums it up. We were asked to read parts of Dianetics in a psych class I took years ago, to see how poorly written, poorly understood work looks and misleads. The psych portions are almost gibberish, and seem heavily plagerized. He almost seems, from what I've read of him, as a sociopath. I do recall and am looking for recent links reading about the sci-fi connection. His sci-fi friend published his works under sci-fi and, if not Hubbard's intent, he let it go just to get it published, it seems.