What is shows is what I consider a disadvantage of the Feud Silo Setup and something that a lot of players miss. That is, just like bombers, silos can shoot at object well outside their own radar. Not many people (could just be observer bias
What I like to do is create a "bubble" of coverage around my silos. If airbases are close by providing immediate protection from incoming bombers, it becomes harder than normal to kill RADAR, yes even if it's outside that ring of nuke launchers. I.e., fill that red line with radar coverage but don't worry too much about extending radar beyond that ring as it becomes useless anyway, at least in the context of AA fire.
This is especially helpful in 1v1 where your neighbors ICBMs must travel over your silos first. Take it for what you will.
Edit: Changed to a much better pic.









