Any weapon system carried on ships has a risk associated with it, and the japanese, with their relatively weak Damage Control, and their emphasis on torpedo armament will inevitably suffer losses from them. Type 93s were oxygen powered and carried a warhead twice the size of most allied types, so this made them very effectiver at sinking ships. if the warhead goes off at the wrong time, its still going to do a lot of damage. but the logic "they are dangerous things, therefore they shouldnt be carried" is just so cockeyed I wonder why we are even discussing it. All weapons are dangerous. The most serious risk for carriers are fuel carried, bombs carried, and aircraft carried. Does that mean carriers should not carry bombs aircraft or fuel? A very dangerous weapon carried by Destroyers with no benefit to a surface naval battle were the ASW weapons they carried. The risk to ships that carried them was very great. In 1939 Ive just finished writing up an account of a British DD, where the holding straps for the DCs came loose, allowing one of the DCs to roll off the stern and explode under the ship, The heaving effect from the detonation caused another two DCs to break free and also explode, almost causing the stern to blow off. Not only that but two other ships nearby also very extensively damaged. On the basis of the arguments being presented here, that means that British DDs were faulty because they carried DCs. Its a totally non-sequita argument, buts its a headline grabber because it looks cute.
Another example of how dangerous own weappon systems can be are mines. The stories of own losses to these weapons are prodigious, but it would be foolhardy to argue that because they are dangerous to own forces, they ought not be used. The best example of their danger in my opinion was the loss of the French ML Cruiser Pluton in 1939. Not only was the ship itesl lost whilst alongside in Casablanca, eight other warships were lost from the explpoding mines. by the logic here, the French should have scrapped all their mine stocks and ceased laying mines. In one month alone, October 1939, mines accounted for the loss of 3 of the 5 Uboats sunk to that point in the war......but without mines there would have been no such losses. Friendly fire is a fact of life, and LL are no exceptions, but neither are they an unnaccepotable risk, given thge benefits they confe4rred.
What isnt brought out are the intangible benefits brought about by Japanese Torpedo techs. Ive read in various accounts that the fear of Long Lance probably lengethened the war by over a year......thats 25% of Japanese resistance capability denied at a stroke. Further, some of their best efforts in air attacks came from their air launched torpedoes, which benefitted greatly by the efforts put into the Long Lance torpedoes. japanese contact pistols and casings as well drive mechanisms and gyro systems were reliable, accurate, strong. Whereas US topedoes required a launch speed of around 90 knots and a drop height not exceeding 60 feet (it got a bit better later on) for a percentage chance of a true run of about 40%, Japanese air launched torpedoes could be launched at 350 knots from drop heights of up to 250 feet, and still have about a 90% chance of running true. These torps used the same depth keeping, casing design etc as the LL. Take away the LL development, and you lose all that.
As far as the argument that the Japanese should abandon half its battlefleet in favour of carriers, and at the same time wave its magic wand to increase pilot outputs. Well for the latter part of the war, that holds true, but in the context of the 1930s, it was simply beyond the Japanese capability to do this. Both the IJN and the USN spent the entire lead up for war preparing for a jutland style decisive battle, the so called Mahanist battles (an American it ought to be pointed out). The US Pacific Fleet was at Pearl Harbour 7th December 1941, for precisely the reason of implementing its Plan Orange strategy....an advance across the Pacific with Battleships the focus. It only abandoned the strategy because the losses at PH forced it to. Nobody expected the makeshift hit and run carrier attacks to work as well as they did.
For the Japanese, faced with severe treaty limits that more or less guranteed US superiority of numbers, and placed very severe restrictions, by category, reducing the battleship numbers is akin to tying another arm behind your back. Scrapping a battleship doesnt mean in the early 1930s that you can build carriers in their place....it just means you have less battleships. On December 29, 1934, the Japanese government gave formal notice that it intended to terminate the treaty. Its provisions remained in force until the end of 1936 and were not renewed. Japan effectively ignored the treaty from the end of 1936 and began to benefit materially from that walk out from roughly 1938. Thats not a lot of time to benefit from a scrapped battlefleet. Certainly not enough time to significantly alrter or improve the carrier numbers or more importantly aircrew numbers
Japans solution to the treaty limits placed on her was to maximise quality. She knew that every ship, every aircraft, every torpedo, had to 3/2 times better than the US material, or better, and she set down the path that entailed. She had probably achieved that advantage by December 1941. She was correct to follow the idea of seeking the decisive battle pre-December 1941, because that was the only way she could hope to defeat the US....a short sharp shock and awe war, which incidentally wasa the same war the US wanted to fight