I found the following as of interest when it came to the fast bowling issue:-
Let's get this out of the way: of all the things CSA has to worry about, Anrich Nortje signing a Kolpak deal is not one of them.
Despite their inexperience, Wiaan Mulder and Lutho Sipamla have adapted quickly to their roles and it was with their support that Nortje enjoyed most of his rewards. Mulder, specifically, described himself as a holding bowler in the first Test, which gives Nortje the freedom to "scatter it" a little, as Shaun Pollock put it, and invite the batsmen to attack even more. "It's very important to bring the run rate down and bowl dot balls because that generally creates wickets," Nortje said.