Just for grins and giggles I checked it out - edited US_NavalBases.mis to set up a KONGO battleship and three large modern tankers in Manila bay. Started career, sank the three tankers, went into port and ended patrol. 31,000 tons, renown 759. Started another career, ignored tankers, sank KONGO, 32,000 tons, 759 renown, same medal. It would appear from that experiment the renown is geared only to tonnage and nothing else. Sink 500 sixty ton sampans and you're as big a hero as if you sink a 30,000 ton battleship.
