ICBMs aren't uniformly randomly distributed across the globe, though. You would only need to cover a few selected orbital inclinations, corresponding to the lat

ICBMs aren't uniformly randomly distributed across the globe, though. You would only need to cover a few selected orbital inclinations, corresponding to the latitude of the launch sites (albeit with a large number of RAs, but probably nothing more than what SpaceX already does for Starlink). The calculus is even better for the most-probable launch scenario, over-the-pole, since all the high-inclination interceptor orbits will converge in the same region as the ICBMs. For SBLMs the calculus is theoretically a bit less favorable, but most of Russia's SSNs will be in the Arctic Ocean anyway to avoid USN attack submarines.