I think the point is that Eliezer's main strength - at least as I expect he would espouse himself - is his rationality or metacognition. This is what he would bring to those endeavours.

In the same way that a clever computer science can be useful to many industries purely through the application of computing, he is hoping that his thought processes can be useful to many different industries, quite separate from actual in-depth knowledge of that particular industry.

I don't think this is a far-fetched idea.

Whether Eliezer is actually good enough to do it is another question, to which I don't know the answer.