Where we find exceptions, it's usually because of an exceptional human at the helm, which of course implies more humanlike and less money-optimizerlike behavior.

Right. So, to a first approximation, humans make reasonable money-optimizers. Thus the "Homo economicus" model.

I think it is perfectly reasonable to say that companies have "agency". Companies are powerfully agent-like entities, complete with mission statements, contractual obligations and reputations. Their ability to make plans and act intentionally is often superhuman. Also, in many constitutuencies they are actually classified as legal persons.