[tater]

It's interesting, your warship data is very close to the mk14 vs large warships, actually, which suggests that the mk14 is about the same as the german weapon.

The most hits on a IJN CL that survived was 2, the least to sink one was 1. So for CLs, the german/american numbers look very similar. 50% of CL hit by 1 mk14 sank, 60% hit by 2 fish sank, and 100% hit by 3 or more sank.

The most hits on a CVE that survived was 4, the least to sink one was 3 (jap CVs/CVLs, and CVEs are pretty mixed up tonnage wise, the one that took 4 and lived, was sunk later (next day I think) by the same sub with 2 more fish, it was also almost 18k tons)

The most hit on a CV that survived was 4, the least to sink one was 1. Avgas and torpedos are a bad mixture.

Your data has CVEs, basically (some CVLs). You had 3-4 survive a single torpedo and one sinking to 1 for sure, but you don't list non-sinking attacks (total loss is NOT SUNK IN THE GAME). Because we don't have the data on hits on warships survived, the data is skewed towards oddball losses. Like the CV above that sank with 1 hit.

For the IJN, 33% of the CVs hit with 1 or 2 fish sank. 42.8% sank if hit by 3 or more fish. You have 60% sunk with 1 fish, but that is only using your "total loss" as the "damaged" that they are. I'm confident that u-boats must have HIT at least a couple more CVEs over the years that did not sink. So I bet the numbers for 1-2 torps sinking CV/Es are pretty similar to the mark 14 with all the data required. Note that the number of ships hit by X fish that did not sink is CRITICAL data to have.

Most hits on a CA that lived was 4, but the fewest to sink one was also 4. CAs, 0% hit by 1-3 sank, 66.67% of those hit with 4 sank, and 100% hit with 5+ sank.

The only jap BB sank was Kongo (really a BC, she was built for speed/armament), and that was 3 fish. The 2 damaged were Yamato/Musashi with 2 each (Yamato took over 10 air-dropped fish, plus bombs to sink).

All told, for warships, the difference is not apparent, and you have not even supplied the required (and really most useful) data of how many hits to NOT sink.

THAT tells you what the DM needs to do even more than the sinkings. If no CA ever took 5 fish and lived, then your DM needs to make sure that 5 hits is 99.999999% fatal. With CVs, the numbers are all over the map, some sank with 1 due to abysmal damage control, or perhaps a design flaw in Taiho (there is a book coming out about her oddball loss to 1 fish).

Anyway, looks like the german fish are not very much more deadly (if at all) vs warships.