Every time someone has said, “This group of people is better, if only we just had this groups of people” they’ve been wrong (whether they were dividing on tribe, religion, skin colour, whatever). I just don’t buy “We only need smart people.” Who is going to decide what smart is? Some smart person? And then it’s a quick downward spiral to “We only need people who agree with me” which is what every such program eventually becomes.
We don’t know what superhuman looks like, and I think we have every reason to believe that we are better off maximizing diversity rather than trying to guess what strength is.