What if the RAF and Fleet Air Arm possessed RP-3 and Tiny Tim rockets in 1939?
Short answerThey could use Fulmars or similar aircraft to suppress defenses before torpedo bombers attacked, especially at Taranto.
NotesThe rockets would create a distinct suppression mission rather than simply replacing torpedoes. A Fulmar or another faster aircraft could dash across Taranto first and fire RP-3 or Tiny Tim weapons at antiaircraft positions. The same attack could damage destroyers and other light ships guarding the anchorage. The slower Swordfish would then enter a less dangerous environment to conduct the torpedo strike.