Why can't the existing team say "no"? Because I hope I didn't make a mistake and hire non-professionals who can't work with others in a professional environment

Why can't the existing team say "no"? Because I hope I didn't make a mistake and hire non-professionals who can't work with others in a professional environment. i define a professional environment to mean setting aside personal and private matters to conduct business oriented tasks. Will personalities conflict? Very possibly. What is a managers job? To manage people (and personalities) in order to achieve results. If there are severe issues with the new hire it may mean that an existing team member needs to go (or the new hire) whichever one is not setting personal/private issues aside...