Hi!
I had some luck in MA with Spit9 against PTs and GVs.
Concernig field defence, one 250 bomb and two rockets + 25-50% fuel.
You could climb to the 3k AGL prety fast which is enough in many cases.
Your best bet is co-op attack. Attack with wingman same time from OPPOSITE SIDES. That one who get GV or PT fire, break out away from wingman and other could make attack run "easy" even with guns only.
If you are alone dive bombing from high straight down with 500-1000 eggs is your best card.
ADD
Dont surprice if GV aint destroy even after 1000 pinpoint bomb... I had see many GVs midle of the create(?) and going well