I don't think this is true. I think the majority of the work that the adjustment does is due to the assumption that high value actions are extraordinarily unlikely.

It's entirely possible that your expectation in situations when you think Buffett is offering $1b is smaller than your expectation in situations when you think Buffett is offering $100. Asking to switch to $100 from $1b misses the point, as by then whether you're facing a charlatan is probably locked in.