One thing that stuck with me in this movie is "The Tenth Man" principle, that goes like this:
"If nine intelligence analysts came to the same conclusion, it was the duty of the tenth to disagree. No matter how unlikely or far-fetched a possibility might be, one must always dig deeper."
I see this as an antithesis to Occam's Razor, where one shouldn't overcomplicate things and try to find the simplest answer. The Tenth Man is supposed to find out the most unlikely answer.
I don't know of this is an actual principle in warfare or if this was just made up in the novel, this could be applied in think tanks and brainstorming sessions. This is actually a way to think out of the box. That's why opinions should not be immediately dismissed as there may be some merit in it.
When the whole team agrees on a conclusion, they could get blindsided. So there should be someone that could explore the other possibilities, even if that person doesn't believe it.
If a decision was based on 99% certainty, then someone will need to explore the 1% uncertainty. In risk management they usually call this stress testing. But even with this, The Tenth Man must challenge the results and go further. A devil's advocate, if I may say so.
The Tenth Man is not actually economical in a business sense, because it could end up as a witch hunt or a wild goose chase on a theory that doesn't make sense in the first place. I guess not many will resort to this, but it is a good method of going beyond the normal thought process.
In budō, this may have relationship to shu-ha-ri (守破離), especially the ha (破) part.