Without occupation, how do you control the power base in the country. What you described is what we certainly did in Japan. But occupation was an essential component.
Also, “influence in construction the new power base in the country”. That sounds like nation building to me. That failed miserably in Afghanistan WITH occupation.
You can appoint a puppet, but he will make a deal with local leaders. “Meet the new Nullah, same as the old Mullah”.
If the folks in Iran will put up with Mullahs running there show, I’d be content with letting them, MINUS the nukes. That seems to be where Trump is.
Afghanistan is a different kettle of fish with its tribal makeup. The Mullahs need to go and that will not happen with a ceasefire. Surrender improves the odds of success, even without occupation. Also, with surrender, troops could go in, destroy all nuclear sites, then leave and let the Iranian people figure it out. If they put the Mullahs back in power, so be it.