From the article:

Suppose we’re torn between multiple moral theories, accounts of which entities are truly sentient, or other broad “worldviews”. How we respond to this uncertainty may be very different depending on whether we opt for maximizing expected choiceworthiness or worldview diversification. The former involves centralized agency, weighing the possible stakes of each option in proportion to the credibility of the theory that assigns it such stakes, and then potentially going “all in” on whatever option yields the best prospect in expectation. Perhaps a good approach for ideal agents, but (I suggest) too risky for the rest of us. The latter alternative decentralizes and devolves power or resources to an ensemble of subagents representing different philosophical worldviews in rough proportion to their credibility. Notice what this does to the usual picture: the moral theories aren’t directly guiding me; they’re guiding the subagents I’ve delegated to. (I’ll come back to this.) By design, this prevents moral “swamping”: you can easily ensure that any credible worldview maintains some power and agency to improve the world by its lights.

I’m a big fan of worldview diversification: I think it is the solution for fallible, non-ideal agents, as we all are. Not only does it avoid swamping worries, but it also avoids the opposite problem of conventional dogmatism neglecting novel moral disasters. We can have a subagent who looks out for shrimp, and another who looks out for the longterm future, and yet another that focuses on the most robust and reliable ways to improve human welfare today. The resources we assign to each can shift in proportion to how credible we find each subagent’s underlying philosophical worldview. And I think someone who undertakes this process responsibly can feel pretty confident that they’re going to do a lot of good for the world, or at least not gratuitously overlook low-hanging fruit.

That’s not to say that this approach is optimal. Just that it’s hard to be confident in what alternative would beat it. I don’t necessarily want to discourage anyone who is more willing to personally go all-in on a neglected high-impact cause area (shrimp welfare, for example). Especially if you imagine what your ideal moral portfolio would look like at the level of all of society, you might well find that going “all in” on the most neglected of your ideal cause areas is — on present margins — actually the best way for you to diversify society’s moral portfolio, and make up for others’ mistaken neglect of important causes.

But I do think we shouldn’t want society to go all-in on any one cause area — speculative longtermism, for example — even if it would seem to have higher expected value than diversification. I think there are several reasons for this. One involves principled hedging against the risk of disaster from miscalculation (especially given a default prior of diminishing marginal value for concentrated funding of cause areas, it seems plausible to me that the objectively correct expected value calculation would support some degree of diversification, whereas our subjective EV calculations could easily go wrong by missing this). Even if expectational reasoning is objectively ideal, we can’t trust human brains to do it right. We need a more diverse portfolio.