I think this is kind of the perennial problem for any nominally altruistic group. I’m not sure how you’d insure against it or how’d you’d even know if it was happening, but I definitely agree EA should at least acknowledge the potential problem having large sums of money and prestige flow through the organisation creates, more so than it currently does.
Personally I think Orwell was wrong that the Soviets’ main problem was Napoleons’ greed (don’t ask me what the real problem was), the semi-recently opened archives give pretty clear evidence that at least the members of the politburo where believers in their cause. So maybe corruption isn’t actually very common in real world altruistic organisations.
I’m not sure there is a another coordination problem that offers greater returns than this.
Also, after the point where hobitisation is moderately common it should be in the interests of individuals to become hobbits. Most of the gains (cheaper housing, longer life expectancy) aren’t externalities.