That begs the question, wht not SA Name - Once per game you can declare you using (this SA). If you do this unit get +2 armour against any subsequent anti-air attack this turn.
Or even
Swarming Attack - for every local friendly aircraft with this ability that is not aborted or destroyed, this unit gains +1 armour. This unit is destroyed if an attaxk against it equals or exceeds its vital armour
But a OPG ability doesn't help it in the long run... You're still (maybe) getting one attack in and if they show up again not getting through. I'd rather spend the extra point or two for the Deceptive Target that is ALWAYS on.
The swordfish you are pitching would be best against cruisers and destroyers rather than the battleships (where the unmodified AA values are less and more apt to not get 6 successes).
IF you are looking to just get that one round of attacks in... what about:
Out of the Sun: Once per game you may declare you are using this ability. It you do all AA attacks against this unit this turn get -2 on their dice rolls. May not be used in Darkness.
This means that there is no reason to have an escort since that additional -1 would be wasted since a SIX would always hit anyways (thus simulating a swarm). The game balance point is that if your opponent had Interceptor they would get the one extra die, however they would need 2 sixes to abort and 3 sixes to destroy the plane. An SA like that I might be able to see at 8 pts... but it would have to be playtested.
Defiant: If this unit is destroyed by a ships anti-air attack, this unit may make a single die torpedo attack against that ship. When thus unit uses this ability, it can't use any other ability on that attack.
Defiant: If this unit is destroyed by a ships anti-air attack, this unit may make a single die torpedo attack that can’t be modified against that ship.
Defiant: If this unit is destroyed by a ships anti-air attack, roll a die. On a 6 the ship that destroyed this unit takes 2 hull points of damage. Torpedo defense works against this damage.
Not a fan of non attack attacks, but it might be suitable