No, it doesn’t sau. By using the upper case for ‘will’, N. made the word a noun rather than a verb. (All nouns are capitalized in German, which is why I thought it interesting.) As a noun, it borders on being religious. I’m surprised that Strauss wrote “complementary man” with man in the lower case, for this reason. Although Strauss was German, he wrote his essay in English, and yet he capitalized ‘will.’
About the ‘complementary man:’ Is he a mirror-image of the true Philosopher, or does he add to the Philosopher in order to make the Philosopher a whole person?
In your OP, you wrote, “The highest, the most difficult problem is that people are abolishing the prerequisites of human greatness—suffering and inequality—and there are no assignable limits to that abolition.” But, it seems to me, you’re only paraphrasing Strauss’s essay when he says, “…at the summit of the hierarchy is the complementary man. His supremacy is shown by the fact that he solves the highest, the most difficult problem…” which, for N. is nature in all it’s forms. Science, in N.'s time, was starting to unravel the ‘secrets’ of nature through medicine, for example, which relieves suffering, and technology, with automation, which started to ‘equalize’ people.
Nietzsche wanted philosophy to be ascendant over science, so he proposed the ‘eternal return’ of everything in Nature in what seems to me to be a coil-like structure, if it were to be diagrammed, rather than a cyclic recurrence. If N. envisioned eternal, cyclic, recurrences in nature, I think he was in error. It’s impossible to abolish knowledge and start all over again from scratch, so to speak. Nature, as in flora and fauna, also evolves. But N. seems very wary of science.
As for any religiosity in Nietzsche, I think it’s there. Nietzsche said the god of Christianity was no longer needed by Western philosophy, which was primarily German. But people have a psychological need for something. Nietzsche gave them the Ubermensch, which Germans didn’t understand and, instead, interpreted as Germany and the Germanic races as superior to all Mankind. The world, therefore, saw the Third Reich emerging in the 1930s and being crushed in the 1940s.
Was Nietzsche nationalistic? From what I’ve read–yes.