Perhaps that very quality of being 'omnibus gifted' in the historic sense of the term-- that is, having global multipotentiality-- may prevent the development of an area of prodigious ability.
I was going to raise this same point. It seems that the unevenness of the scores plays a significant role, because if a child has a limited skill set, they would naturally focus on those skills and develop them further. A child with a broader skill set would enjoy a larger number of pursuits, sampling them all to different degrees and seeking novelty over perfection.
