Torpedoes have always faced many issues in actual combat. For example, if the torpedo is too large, its resistance in the water increases, and the requirements for buoyancy rise, making it very difficult to design heavy torpedoes.
They not only need a high-pressure air chamber capable of automatic pressure adjustment to ensure buoyancy, but also an independent thermal power chamber to maintain stronger propulsion, which are all design challenges.
However, if the size of the torpedo is reduced and its shape is changed, it can indeed move quickly and steadily in the water, but its damage becomes quite limited.
A forty-pound torpedo could cause some damage to warships, with most instances of piercing below the waterline coming from torpedoes. However, all countries have corresponding measures, which involve segmented sealed bottom compartments.
If a spot is unfortunately pierced, they quickly seal the compartment door at that location, so more water doesn't flood into the hull.
