To answer your question, the SA Pilots really are terrible and most are imposters as you so mildly put it. They are also extremely arrogant and very racial. No Korean F/O enjoys their flights with a SA in the left seat!
The Aussies are just as bad, but on the positive side their credentials are at least real. The Aussie Captains who made it to the rank of Line Check Pilots (LCP's) were after a period of time, removed from their positions as management soon realized their mistake in appointing them LCP's in the first place.
Management does eventually listen, but it takes postings like this to bring certain matters to their attention.