I've been in simular situations too. The damage model seems a bit iffy at times. I put 4 torpedoes into a large composite, equal spread right down the length of her and she kept steaming at 10 knots, not even a list. I shoot another one, messed up the spread, so the 2 fish only bearly clipped her bow and down she went like a rock. Another ship, small composite I think, I put 2 fish in her aft end, blowing up the ridder and the screws (neither visible in camera mode) but she still did 10 knots and was zig zagging away!
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