I did some testing using the "new merchant fleet" test mission (unescorted convoy). I first went back to my original mod list:
TWoS Encrypted BdU Orders
TWoS Remove Map Plastic Cover
TWoS Remove Sub Flags
TWoS SM Interior_Food Stocks
TWoS Real Navigation
Critical hits 1.1 Torpedoes
TWoS FX_Reduc. Fires and Expl
My idea was to run the mission a few times to see how many ships sank with one torpedo. And then run the mission few times with the
one ship, one torpedo v1.00a mod to see how much the results differ. With the original mod list I fully expected to sink ships with only one torpedo as before. But the results I got were very different.
I ran the mission five times with the following results:
Torpedoes fired: 32 (All Atos, depth 2m, impact pistol)
Duds: 4
Misses: 7
Hits: 21 (21 different ships, one torpedo each)
Of the 21 ships hit, 12 were sunk and 9 survived. The convoy included a 19000t liner and a 11335t T3 tanker. Both were hit in all 5 missions, each was sunk once and survived 4 times.
Not sure why the results are now different with the same mod list. I'm confused.

The Rawalpindi merchant cruiser still goes down with one torpedo each time in the RAOBF mission.