How do I keep control of a courtroom full of strong personalities?

Holding a room full of strong personalities is genuinely hard, and struggling with it does not mean you lack authority. It means you have not yet found the version of it that fits you. Authority is not volume. Some of the people who command a room most completely never raise their voice. Real control comes from clarity and consistency, not from overpowering anyone. When people know the rules, know you will hold them evenly, and see that you do not rattle, they settle. The personalities test the boundaries because they are looking for where the edges are. Show them, calmly and every time. Choose one clear standard for how your room runs and enforce it the same way with everyone, no exceptions. Predictability is what makes a room feel safe and orderly. You lead not by being the loudest, but by being the steadiest thing in it.