It seems worth distinguishing ‘effectiveness’ in the sense of personal competence (as I guess is meant in the first case, e.g. ‘reasonably sharp’) and ‘effectiveness’ in the sense of trying to choose interventions by cost-effectiveness.
Also remember that selecting people to encourage in particular directions is a subset of selecting interventions. It may be that ‘E not A’ people are more likely to be helpful than ‘A not E’ people, but that chasing either group is less helpful than doing research on E that is helpful for whichever people already care about it. I think I have stronger feelings about E-improving interventions overall being good than about which people are more promising allies.
Do you have quantitative views on the effectiveness of donating these organizations, that could be compared to other actions? (Or could you point me to any of the links go to something like that?) Sorry if I missed them.