If my Philosophy memory sticks with me, I think Nietzche was critical of the systems that encouraged belief but did not transmit behavior. Christianity for example in "God is Dead". I think Nietzche's critique of Christianity was that rather than teaching us to believe in Christ, it should teach us to be like Christ. My point was to state that ideological beliefs should begin with emulation. I think often in aikido we have either "everyone is right and everyone is great...in their own way." Or, "I can never be like shihan X." Neither solution is correct, yet both are philosophically valid.
My point with Superman is that our modern culture considers him to be so unreachable as they can reduce his superiority and he stills remains a super-man. I remember a dog racing story that implies successful dog races happen when the rabbit remains just ahead of the dogs. Not too close or it is caught, but also not so far ahead as the dogs give up. Our training should constantly set to improve our skills, but never extend so far beyond our skill as we give up.