Well... JANAC didn't shaft every sub in terms of tonnage, just look at Archerfish.
JANAC: "We're sorry Archerfish, you did sink that 800-ton frigate but according to records, you didn't sink a Hiyou-class carrier."
Archerfish: "Ah man."
JANAC: "You sunk a Yamato-class carrier."
Archerfish: *spit-take*
WHAT!?War timeTangTonnageYou are merely fourth placeAfter the warA comparison between US and Japanese records shows that Tang only sank 93824 tonnageSo she was exaggerating her record all the time...Yeah...It can't be helped, I will end myself with my own torpedo! The total sunk tonnage will surpass the first place when I add my own tonnage in it...!Record holder of most tonnage sunk by US submarine!