By fooling A players into thinking they're As? Hard, but I'm sure it happens.
However most of it might be convincing Bs they are Cs ... and what happens after that is not pretty for the hiring B, I suspect.
One likely characteristic of Bs is less than total honesty, with self and others.
Yes, I'm being facetious. But even fortune-cookie level business advice should pass basic sanity checks like this one.