All 3 were put out of action for considerable time at a critical juncture of the campaign, I'd say that was the definition of success especially with only 20 aircraft committed. That they were not sunk was thanks to being close to land and able to run themselves aground. Success doesn't have to be defined always as tonnage sunk, thus the credit for also disabling the Bismarck. They also played a role as gunnery spotters in the Norway campaign allowing Warspite to put 8 destroyers out of action, nearly half the entire German destroyer fleet. I'd chalk that in the success column for a anti-ship credentials of a very versatile plane.