1. Aircraft vs flank speed
Setting dive bombers as level bombers will lead to unrealistic attack tactics. What if we fit them with some fast-aiming but short-ranged dummy gun, whose muzzle flash effect will spawn a bomb?
2. MAD ideas
Have you checked that visual sensor's detection angle does not prevent if from "seeing" directly below the plane?
3. Sinking torpedoes
Have you tried testing with Swordfish planes (and, indeed, with IRAI installed, no other mod overwriting its files)?
IF they use torpedoes affectively, I would try messing with various parameters (aircraft max speed, position of the torpedo bone, drag coefficients, min height, ect) until I find the one(s) which break their ability to use torpedoes in a prope manner.