So if an engineering team is successful, then their manager is necessarily an engineering expert? You’re really not providing any rationale to support this rather extreme position. Bill Gates experience in the field of public health is choosing projects to finance, and even then he is not the primary person responsible for that in his foundation. Bill Gates has no credentials you could point to, and has done no work you could point to, that would support an assertion of him being a public health expert. It is frankly a ridiculous proposition.

>He has done no work you could point to

His work in eradicating Polio. Choosing which projects to finance is a skill in itself, something he's likely more capable of than a traditionally credentialed expert. I can't help but think that you have an arbitrarily narrow definition of expertise.

What public health expertise do you believe Bill Gates personally contributed to the The Global Polio Eradication Initiative? As far as I can tell, Bill Gates contributed $110 million USD to The Global Polio Eradication Initiative in funding, but personally contributed no polio eradication expertise at all to that project.

There is no basis at all for claiming he’s a public health expert. He might be an effective philanthropist, but that’s a completely different topic.