An understanding of the role of the SANDF in terms of its constitutional mandate is required before far fetched ideas of military detectives solving crime in the Cape are raised. 
Section 19.(1) of the Defence Act requires that the Defence Force may be employed in co-operation with the South African Police Service in terms of section 201(2)(a) of the Constitution in the prevention and combating of crime and maintenance and preservation of law and order within the Republic.
The President and Min of Defence and Police must specify where such deployments will occur plus other requirements of the Defence Act.
The SANDF may so deploy to the Cape Flats area but will do so based on an SAPS generated plan of operation with  CJOps operational inputs in respect of troop levels and possible tasks.
Those tasks would typically be assisting with cordons, protection of police road blocks and vehicle checkpoints plus combined patrols.  The police remain responsible for crime investigation.