you might be able to hit one but it'd be pretty impressive, like firing a bullet and hitting someone in another country impressive

I'm not a rocket scientist, but I guess even a single lunch in the retrograde direction should be enough. You lunch a box of ball bearings with a plastic explosive to spread them out, and then just wait. The cloud will pass over Iran every 12h or and will stay in orbit for quite a few weeks, since the orbit is even higher than ISS reboosting once a month, and balls are highly aerodynamic compared to the Starlink flat sails. The cloud won't be very big, but it will repeatedly swipe through quite a lot intersecting prograde orbits. I guess the chance would be quite high. Iran can also split payload into smaller boxes and "deploy" then in sequence while the second stage is firing, then detonate them, to spread out even more.