Not sure I can help without giving facetious answers (don't be in range, go with a dedicated AAW platform or two, ride along with a CVBG etc.)
I
believe the RA Perry's Standard Missile was made to be less a of 'god-mode' weapon, so I've gotten used to it. I thought the stock SM was better performing?
It does change tactics - one ASM, torpedo or air attack and the Perry's toast. It's annoying too, because even if it's not a fatal shot, the missile launcher will most probably be knocked out in the first hit, and then you just have to wait for the
coup de grace...
Without being silly, does using one of the freighters as a shield work? It might absorb a missile or two and you can then shoot down the Backfire?
It's interesting for a discussion about tactics
Stew