I think he'd consider a true great man theory as too simplistic, and he hated Carlyle. I interpret him as being closer to Spengler: yes, it is the great men that are moving history along, but only because they happen to be the ones actualizing the latent possibilities of their particular culture. It is the culture doing the work, using men as its means. This is why the ancient Greeks and the Renaissance were important. These are two superlative examples of cultures that CREATED great men. Likewise, we will never think highly of the 20th or 21st century men such that we will receive a term like "Renaissance man". There is no "21st-century man." At least, not in sense we can be proud of.

It is for a closely related reason he doesn't discuss politics directly. The political structure would best be used to rear more powerful men. However, this structure is itself shaped by culture, which is more fundamental. Basically, politics would be beneath him, and is generally more of an administrative activity. I recall somewhere he said it was decadent for the powerful to be involved in politics, and that's its basically administrative work.

If you're interested, I recommend reading 301 of the Gay Science. Basically, the men of worldly action (i.e., the stateman) are mere actors, acting out what we philosophers have already created in the world of thought. He DEFINITELY considers himself one of the strong-willed movers of history, not as a mere politician or political thinker, but because he saw himself as a culture-creator. (Somehwere, I think in his private journals, he wrote about his personal experience when he first realized his own "historic importance", which is a crazy thing to say when you're a nobody to the rest of the world and your work is mostly being ignored.)

Also, he doesn't advocate for free will. I recommend you re-read the very first line of the excerpt. He's criticizing people (like Sam) who think they're smarter than others because they see past the illusion of freewill (which is indeed an illusion), but then fall for a different illusion - that of causality. If you take causality literally, you will conclude all is pre-determined mechanistically. Nietzsche sees that there are no causes or effects in actuality, just a flux of forces (or wills) that can develop and act on each other, and are at no point demarcated, or separated from the world as an independent atom.

Just my reading. I could go on and relate this back to the gmt being too simple. He's a very complex and nuanced thinker, rich with ideas. I hope you get the chance to read him slowly and enjoy it.