Either: 4x Red Squadron, 4x R7 Astromech
or
3x Red Squadron, Tarn Mison, 4x R7 Astromech
Or replace one with Biggs.
Against a two ship list you could kind of just tank damage if you target locked the right ship. Against BBBB(Z) you'd have a pilot skill advantage.
Tarn is quite hard to kill, but if you correctly guessed which ship was going to fire at you, your Red Squadron pilots would in effect be your standard 25 point Tarn Mison.
What's the math on using a target lock defensively? How does it compare to just being a B Wing and having more health?