Some so-called motivational speakers don’t have much stories to share. Thus, they share someone else’s stories. They simply retell the accounts of other successful people, which they probably read in a book or saw on Youtube. But who are they to represent these personalities anyway? What you need is someone with real stories. Your audience is intelligent enough to know whether the inspirational speaker is authentic or fake. In fact, they can feel the sincerity of lack of it. Again, investigate.