Can any arbitrary [able bodied] human become a genius across multiple
disciplines or at least one discipline assuming that they have some
Secondary Eduction in these disciplines?
No, not all able bodied humans will be able to be become a genius across one or more disciplines. Assuming genius in this context means someone achieving international acclaim for their accomplishments in a specific discipline, only a very small number of able bodied humans will be able to achieve this. This kind of rare accomplishment requires an uncommon interaction of intellect, work rate and opportunity amongst other factors, which is why most people do not achieve it. I am happy to expand on this answer if you want further clarification.
Ok, let me reiterate what I said, but maybe make it clearer. Before I do that, I would just like to also add that one of the challenges with answering this question is the subjectivity involved. For instance, what are exceptional problem solving skills? For now, I will assume that you mean good enough for meeting the admission standards for one of these top level business schools. Assuming this is what you mean, I would still argue that not all able bodied humans will be able to develop exceptional problem solving skills across one or more disciplines.
Getting accepted to one of the business schools (i.e., demonstrating exceptional problem solving skills) is something that only the top x% of applicants will achieve. In developing these exceptional skills applicants will have benefited from the positive contribution of several different factors (what I referred to before as "the uncommon interaction") such as their intelligence, physical and mental health, network, discipline, confidence. For instance, probably few or none of the applicants will be of average intelligence (e.g., having an IQ of 100), have got severely, or regualarly sick, had severe depression, had to work extensively to support their family, had bad role models, had below average discipline or self-belief etc. While some may have been disadvantaged in some ways (i.e., maybe they did have to work to support their family), these applicant will likely have been able to counteract this through advntages in other factors (i.e., being exceptionally smart). In summary, as this example hopefully serves to show, those who are able to get exceptional scores are those who have had exceptional combinations of the different factors. By definition exceptional means not normal, therefore it would not be expected that such achievement would be within the reach of any able bodied human.
Having said all of this, what I will add is that most/many average individual ( interms of IQ/available time/movtivation etc) probably could probably become exceptional in one or more areas if given enough time - it is just that it would take a very long time for them to learn enough to be exceptional. Additionally, it would be most/many, but not certainly not all as some people (i.e., the unmotivated, the sick, the homeless etc) would have disadvantages that would prevent them from succeeding.