@Yomanyo this isn't plot armor because it's a law that makes sense that can be inforced. That the best Knight is to take the lead to protect the imperial family him being that means he leads. Also no other person volunteering for the responsibility of taking care of the imperial princess in a completely unknown area. Where they would be blamed if something were to happened to her. Most people pettiness turns down when their lives are in danger. It the princess choice as well so it had nothing to do with group thoughts. It's later discussed she's willing to trust anyone if it saves the people.