From what I recall land missiles (minuteman) does its own alignment while in the silo to give it what it needs to hit that window in space where the RV detaches. There some documentation and YouTube videos depicting the alignment process.
Yup. But that’s based on knowing where the silo is, they are less mobile than subs (or trucks or trains). The alignment is all based on dead reckoning from where it started to where it’s going to know where it is, where it wants to be, and how to steer there.