I will argue to the contrary. For reasons I will never know he came to speak in my home town. Someone put up some pre primary bucks I guess. There were no Uhh pauses. He spoke for an hour and a half extemporaneously with no notes.
He never stood behind the podium but rather roamed the stage, mic in hand, making point after point, after point......... all while making eye contact with his audience. As a speaker the man is in fact superb.
He sold me. He has a fantastic story of being a project raised afro heritage boy that became an extraordinary surgeon and administrative executive..
If I’d ever seen him speak the way you describe - even once, among the many times I’ve seen him speak to national audiences - I expect I’d feel somewhat differently about his speaking style. But it’d have to be WAY more than an occasional one-off for him to be an effective running mate.