How does this guarantee a political and strategic win for Iran?
Iran was already teetering on the edge of being a failed state: socially, economically, environmentally, and agriculturally. Iran is expending expensive ballistic missiles to force those THAAD and Arrow shoot-downs. Yes, they're winning the shot exchange ratio, but their economy is orders of magnitude smaller than the US. Besides, unlike the Gulf states, the US and Israel are not just sitting around playing defense. They are systematically destroying substantial fractions of the Iranian war machine and have both threatened and attacked domestic and international energy production, the lifeblood of the Iranian economy.
The only true winner of this war, however it shakes out in the end, is Russia. All of the Middle Eastern powers aligned with the US are going to be desperate to rebuild their interceptor stockpiles and will surely get priority over Ukraine, likely for a very long time as the production rates are very low as you've pointed out. Plus, Russian gas and oil are worth a lot more than they were prior to this war, and are being allowed to trade more openly as well.
Iran already bled enough high end regional interceptors, the strategic balance is if they can build enough moped shaheeds that can be assembled in garages to overwhelm whatever comes in theatre. And we know upper limit of US+co interceptor production for next 3-4 years. Economic size =/= productive capability. Ultimately Iran with survivable regional strike complex can existentially threaten gulf state adversaries who are all dependent on desalination while Iran, as shit as their water crisis is, is not. UAE, Qatar Saudi and Israel are like 70-90% desalination. They can threaten Iran economic lifeblood, Iran can literally end their lifeblood. Iran simply has massively more lethal/credible escalation dominance vs GCC. Iran already being failed state ironically allows them to escalate harder - they have much less economy to lose, vs GCC losing economy and biology.
Ultimately if Iran locks down Hormuz long term they can transit tax their way to prosperity, and if they can convince PRC to be enforcer of petro-yuan (big if), they'll basically get unlimited hardware to do so. Not that burning bridges with GCC is PRC first choice, but if Iran can lock down Hormuz, they have leverage to compel PRC to accept arrangement because it's worse than no Hormuz energy. The spoiler obviously is US who would rather toast GCC oil than lose petro dollar. Or Israel being nuke happy.
Iran was already teetering on the edge of being a failed state: socially, economically, environmentally, and agriculturally. Iran is expending expensive ballistic missiles to force those THAAD and Arrow shoot-downs. Yes, they're winning the shot exchange ratio, but their economy is orders of magnitude smaller than the US. Besides, unlike the Gulf states, the US and Israel are not just sitting around playing defense. They are systematically destroying substantial fractions of the Iranian war machine and have both threatened and attacked domestic and international energy production, the lifeblood of the Iranian economy.
The only true winner of this war, however it shakes out in the end, is Russia. All of the Middle Eastern powers aligned with the US are going to be desperate to rebuild their interceptor stockpiles and will surely get priority over Ukraine, likely for a very long time as the production rates are very low as you've pointed out. Plus, Russian gas and oil are worth a lot more than they were prior to this war, and are being allowed to trade more openly as well.