I don't think you have to assume that CEO-ness is evenly distributed.
I can even believe that kids born in Singapore have more CEO-ness in them on average than kids born in eg Indonesia or PR China. Even if for no other reason than that Singapore is the kind of place that's comparatively more tolerable / less horrifying for the kind of people with CEO-ness traits. (It's also pretty expensive, so only rich people can really afford to have kids here.)
(I'm assuming here that CEO-ness runs in families.)
In any case, the rest of your argument still makes sense, even if someone born in Singapore statistically has a 3% higher chance of becoming a CEO than someone born in Portugal or whatever.
I can even believe that kids born in Singapore have more CEO-ness in them on average than kids born in eg Indonesia or PR China. Even if for no other reason than that Singapore is the kind of place that's comparatively more tolerable / less horrifying for the kind of people with CEO-ness traits. (It's also pretty expensive, so only rich people can really afford to have kids here.)
(I'm assuming here that CEO-ness runs in families.)
In any case, the rest of your argument still makes sense, even if someone born in Singapore statistically has a 3% higher chance of becoming a CEO than someone born in Portugal or whatever.