For low level shipping attacks it helps a lot if the planes being used have a fair degree of agility, may not need to be fighter like but 4 engine bombers may leave something to be desired. This is from wiki on the Beaufort so take it as you will.
" A successful torpedo drop required that the approach run to the target needed to be straight and at a speed and height where the torpedo would enter the water smoothly: too high or too low and the torpedo could "porpoise" (skip through the water), dive, or even break up. Height over the water had to be judged without the benefit of a radio altimeter and misjudgement was easy, especially in calm conditions.[34] For the Beauforts using the 18-inch (450-mm) Mk XII aerial torpedo, the average drop-height was 68 ft (21 m) and the average range of release was 670 yd (610 m).[35] During the run-in, the aircraft was vulnerable to defensive anti-aircraft fire, and it took courage to fly through it with no chance of evasive manoeuvres. The Beaufort's optimum torpedo dropping speed was a great deal higher than that of the Vildebeests it was replacing, and it took practice to accurately judge the range to, and speed of, the target ship."
Now do you really want to be flying B-17s at 60-80 feet above the water on attack runs? AND getting within 700 yds of the target ship? Might work great on the unarmed slow transports that are Mr. Benders favorite targets but in order to hit the transports you might have to fly even closer to an escort, even if all it has is a couple of 25mm AA guns.