Juno wasn't sunk by the Luftwaffe - but by the Italians!
Greyhound wasn't hit and sunk by ONE bomb...but by three.whilst destroying HMS Greyhound with a single hit
Fiji is actually a perfect example of the AA fire issue; she was left dead in the water by the initial attack...BUT only sunk later AFTER she exhausted all her AA munitions.The Ju 87s also crippled HMS Fiji that morning, (she was later finished off by Bf 109 fighter bombers)
Hereward is a strange case, there is some contention as to her eventual fate. Certainly an attack by Stukas left here dead in the water...but her situation was confounded by Adm. Rawlings who decided not to turn back and take her in tow but instead to press on out of the area. She was last SEEN to be heading back to the coast of Crete...thus under her own power again, and fighting off continuing attacks - as one of the reasons Rawlings decided not to assist was that the coast of Crete was only five miles away.
There is however a different account by Bragadin that Italian torpedo boats in the area were closing in to finish her off when she exploded; the MAS boats then began rescuing survivors. If she required "finishing off" - then while the LW may have crippled her and continued to attack, she sank as a result of an explosion on board after the air attack had finished.
So from that list of ships - Greyhound, Fiji, Kelly, Gloucester and Kashmir were confirmed sunk by the LW. However - Fiji sank but only after she could no longer defend herself, the same fate as Gloucester, which was sent back into the area depleted to only 20% of her AA munitions. Hereward was certainly crippled by the LW, but there was no confirmation that her final death was a direct result of the continued bombing as opposed to the earlier damage she suffered.