Mr. X is convinced of himself. One small problem: he finds it difficult to convince the others. Why?
Public speaking means connecting with the audience. But how? Where is the problem? Is it a muscle stiffness that needs to be soothed or a bad habit that comes out because of uncertainty? Is it a lack of awareness of the space and the audience? Or is it the dramaturgy of the speech that is not structured well enough?
We can solve all these problems together. The prerequisite is that the aim is clear and ethically acceptable to both you and me. Rhetoric is a powerful weapon. Not everyone should use it.