This application highlights a problem in that definition, namely gains of specialization. Say you produced humans with superhuman general intelligence as measured by IQ tests, maybe the equivalent of 3 SD above von Neumann. Such a human still could not be an expert in each and every field of intellectual activity simultaneously due to time and storage constraints.

The superhuman could perhaps master any given field better than any human given some time for study and practice, but could not so master all of them without really ridiculously superhuman prowess. This overkill requirement is somewhat like the way a rigorous Turing Test requires not only humanlike reasoning, but tremendous ability to tell a coherent fake story about biographical details, etc.