Just focusing on the reputational effects, my quick guess is that the extent to which a donor/public figure is ~memetically connected to the movement/charity is really important, and I expect that most Giving Pledge signatories are significantly less connected to the Giving Pledge (or American higher education donors to American higher education) than the biggest ~5 EA donors are to EA. (Note that “EA donor is also a poorly defined category.) Without considering this factor, we might conclude that getting more donors adds significantly/unchangeably to ~scandal-based risk levels, or that the number of donors is the key thing to consider. I think this would be a false conclusion; more donors probably means that each is less central (which I think would also have the benefit of reducing the influence of any given donor) and because the public profile of the donor(s) probably matters a lot. (I do think there are separate ethical issues and considerations involved in taking funding from UHNW donors.)
We explored related questions briefly for “Are there diseconomies of scale in the reputation of communities?”, for what it’s worth (although we didn’t focus on donors specifically). See e.g. this section.
Just focusing on the reputational effects, my quick guess is that the extent to which a donor/public figure is ~memetically connected to the movement/charity is really important, and I expect that most Giving Pledge signatories are significantly less connected to the Giving Pledge (or American higher education donors to American higher education) than the biggest ~5 EA donors are to EA. (Note that “EA donor is also a poorly defined category.) Without considering this factor, we might conclude that getting more donors adds significantly/unchangeably to ~scandal-based risk levels, or that the number of donors is the key thing to consider. I think this would be a false conclusion; more donors probably means that each is less central (which I think would also have the benefit of reducing the influence of any given donor) and because the public profile of the donor(s) probably matters a lot. (I do think there are separate ethical issues and considerations involved in taking funding from UHNW donors.)