There is nothing wrong with the picture. It seems to me that those are the people you have chosen as mentors because they are experts in a field that you were looking for mentoring. All of them are sharing part of their PT knowledge to help us becoming better personal trainers. Their area of expertise is the human body and the way it functions, and PT training is an excellent base for that.
There are others who are PhDs in exercise science who have greatly influenced me, and the first person to come to mind is Len Kravitz. I will never forget the first session I attended with him when he, in his very special way, described the metabolic pathways. I had stitches laughing and never forgot it.
At the last IDEA World Fitness Convention, I had the privilege to listen to the surgeon general Dr. Regina Benjamin who was very inspiring to me with her personal story and her vision for the future.
And I certainly agree with Joanne in singling out Kathie and Peter Davis as fitness industry leaders.
I believe there are many more, and we just pick and choose those that are the closest to our own wants and needs.