When I joined I got a reply from another South African author and I gave him Kudos for being published, even self published.
The reason for this is that in South Africa your local publishers are restrictive in content and genres, and your international publishers focus on specific genres of interest from South Africa while anything else goes in the same bin as every other applicant.
In essence this means that if you take up the niche then you have a decent chance, if not then you have perhaps a slightly less chance overall than a local US or European submission to those in country publishers.

The niche tends to be non fiction, local languages and / or cultural books.
I know several South African authors who thrive with that kind of work.