The problem is that you're using names as a proxy to ask whether two people are the same. If I ask you: "in this film, are Will Smith and Will Smith the same",

The problem is that you're using names as a proxy to ask whether two people are the same. If I ask you: "in this film, are Will Smith and Will Smith the same", you do not have enough information to answer, because there are at least 74 Will Smith's on record in film credits: https://www.imdb.com/find?q=will%20smith&s=nm&exact=true https://www.imdb.com/find?q=will%20smith&s=nm&exact=true And this is from an industry with guilds and unions to try to ensure that no two credits have the same written name. You can make a very good guess, but names can't tell you enough to determine if these two people are the same or different. One person can have many names, and many people can have the same name.