They could be totally unrelated to each other. Just because they have similar names, it doesn't mean that they have any relationship to each other. It's entirely possible that some overeager "genealogist" scraped the name off the Internet and connected it to his/her family tree just because it superficially appeared to be the right guy. Then 30 other people copied the error. It happens all the time. You need to proceed one step at a time and use reliable sources (not online family trees). Start from the generation that you're absolutely certain is correct. Then proceed backward from there. Obtain records from that person's known place of residence to try to obtain his parents' names. Use original sources (e.g., microfilmed church records), not online indexes or trees.