This statement is false.
While it always is valuable to have a knowledgeable person in the group on a particular subject, they should not take charge and do most of the speaking. Effective dynamics in group work come from collaboration and cooperation between everybody, not just one person. In a successful group environment, it’s important to ensure everybody’s input is encouraged and valued. Encouraging different perspectives and viewpoints leads to better chemistry and more points of view.
Effective leadership comes from facilitation of ideas and communications, meaning while one person is in charge, that person is not doing all the work by themselves. Rather than attempting to have one person take over the entire conversation, it’s important that every member of the group participates equally so that collective intelligence leads the way.