EDIT: Nevermind…had to read your post a couple times to comprehend. The BARCAP hijacking is a proven method indeed.
Also, you can frag OCA Strikes against locations that have EW radars (airbases, depots, army bases, etc.) and as long as someone takes out the primary target while you take out the radar, you should still get a good or excellent rating. As for leftover EW sites within SAM battalions that have the tracking/missile radar already destroyed, DEAD is definitely the mission you want. SDBs are brilliant for picking off the EW radar and any leftover launchers/AAA, etc. I just performed this very task against a SA-3 site that had the Low Blow previously destroyed and got an excellent rating for taking out the Flat Face, three launchers, and a few support vehicles with SDBs.