I may have misread the article. I thought the estimated cost of the separation was 2bn spread over 8 quarters. They may not spend it equally each quarter but it would add to +/- 2bn.
In the grand scheme, it is not a lot of money for BBK:
1) 1Q19 PBT was 2.9bn so the full amount could be covered by a single normal quarter if they so chose.
2) Some costs may be covered/reimbursed by ABSA (SA).
3) Some costs are for upgraded systems which will benefit them for many more years.
4) Training costs on upgraded systems would have been a cost regardless of the separation.
Greedy when others are fearful. Very fearful when others are greedy - to paraphrase Warren Buffett