Not to say that I am against this cause but this is a false equivalency between physiology and pleasure. What ratio of total erogenous tissue is removed in each procedure, and what impact does it have on ability to achieve an orgasm, as well as pleasure? Is it still higher for male circumcision relative to FGM along these measurements?
Murder is not a global top-10 cause of death or suffering. Sexual abuse could very much be a global top-10 cause of suffering based on Akhil's post.
There is also this theory that wheat is the driver of the agricultural revolution which ostensibly was the start of human civillization, that I think I read in Sapiens. I also know that golden rice, which was genetically engineered to contain vitamin A, was predicted to improve the vision of hundreds of millions of children, though the intervention failed because of negative campaigns. Based on that, maybe an impactful intervention would be to find and engineer an even more effective crop to grow?