SAA, the ultimate owner of both, is kept on life support by infinite amounts of government - sorry - taxpayers' - money, so I think it unlikely that either Mango or Sax will be allowed to fail, particularly since they seem to run on more businesslike lines than SAA which is the ANC's private taxi service to ferry the club members and pals between JNB and its dwindling number of international destinations.
I would be very sorry indeed to see Mango go. I've used them a lot and hope to continue to do so.