Have you inspired a B-Candidate to be an A-Candidate?

We have seen articles about hiring A candidates, who in turn hire A guys or A+ guys. If you hire B-candidate they in turn will end up hiring B candidates or B- or C candidates.

In startup scenario, have you seen or have you inspired B candidate to be an A candidate, could you please share stories successes and failures in doing so?

For example, I am trying to find cases in startup companies similar to Seabiscuit(Movie/Horse) which is physically average horse winning triple crown and its trainer, jockey and owner are even greater for accomplishments with Seabiscuit.