If JZ gets impeached, he will loose his state pension and his security at his citadel.
He knows that this is possible and may step down instead to avoid that but he may hang on for his pals to pay for the Nkandla non security improvements.
One problem with that. If his pals donate him the money, then he has to pay a further 40% odd extra as donations tax.
At this moment he is one scared president. He knows now that he cannot make any changes to ministerial portfolios and the NEC also knows this after the Concourt ruling where they were themselves rapped on the knuckles.
So in effect, JZ has of now no power and his pals will distance themselves from him. He is on his own now. Left to his own demise. Good riddance JZ and go herd your cows until the can of worms opens further as it will.