Be wary of any "per-capita" statistics. Statistically, averages work only if distributions are symmetric. Mean is a poor indicator of an asymmetric distribution.
So, the question is - Do we have symmetric distributions for talent within each geographical area? We see similar arguments in sport but the assumption of symmetrical (normal) distributions for talent within a geographical area is most likely not the case [0]. There are many other factors like income, population density and "coaching" centers that lead to existence of asymmetric distributions. Hence, "per capita" statistics are quite meaningless and mask the real factors that contribute to Nobel Prize winners.
Primarily, the proportion of GDP to research and scientific activity are a better measure to compare countries against [1]. That ensures that most predictive factors are accounted for.
[0] https://www.frontiersin.org/articles/10.3389/fpsyg.2018.0274...