I often wonder if there are points in human understanding where there is an opportunistic amount of existing knowledge, current exploration of knowledge, and sets of ideas floating around that lead to these sorts of surges of shared ideas and principles in disciplines.
While it's no doubt from accounts Nuemann was brilliant, I've observed other brilliant people who I feel could be ground breaking minds given the right set of circumstances.
A bit of nature vs nurture, environment vs natural talent. I feel as though humanity often has the Neumann, Einstein, Euler, Ramanujan, etc. but need the right set of circumstances to really shine through. They could just be outliers but when you see a collection of these sort of minds during a time period, I can't help but think there is an environmental factor enabling it. Even people as brilliant as Newton had some equivilance in Leibnez with the invention of calculus (Newton was clearly above and beyond though).