HARMs have some form of inertial guidance capability, as well as a ridiculously wide FoV last I checked (but not necessarily confirmed with good sources). The self-protect launch mode for the HARM even allows for shots against threats behind the 3-9 line, at least IIRC.
The pre-briefed mode allows you to launch the missile from quite far away, with a pre-programmed threat for it to go after - you're basically launching against a threat that might not be emitting yet from far away, and once that radar turns on, the HARM will go after it.
Got a question about ARMs in SAM sim. I don't know about the Shrikes in the Linebacker scenarios, but HARMs pop up slightly after they're fired, so shouldn't they leave the FoV on the targeting radar when they're launched at you in SAM sim?
