People may not consider clerical employees as the ones who cause the major financial scandals but they do have a very important role to play here. A fraud requires a considerable amount of time and usually it is the one with the financial control teaming together with many employees working under him to implement it.
Rotating clerical jobs helps in strengthening the control procedure in two ways. One is that no person, even though he may be at a lower post, gets to know the system so well that he can manipulate it for his own good. Several small financial problems could result in the same outcome as that of a single large financial crisis.
Also, as people at the clerical position are aware of what their seniors are doing, they can avert any disaster. But working under the same person for a long time makes it easier for those above them to coerce and threaten them, which prevents them from bringing into the open any underhand activity going on.
If the clerical employees work under different managers and know that they would have to move on shortly, it would be difficult for anyone to influence them, using rewards or punishment, to suppress the actual facts.
Some organization, particularly government departments do use the practice of rotating its clerical and other employees to different positions periodically as a means of controlling deliberate dishonesty among such employees. the extent to which this practice actually achieves the desired objective of controlling dishonesty and corruption among public servants is open to question.
The logic of transferring is that a dishonest person, to be able to engage in corrupt practices without being "found out" needs to develop a nexus of other employees to collude with him or her. Also such an employee need to develop and understanding with the the persons from whom illegal gratifications are received. All this takes some time. It is assumed that when a person is transferred frequently enough, he or she may not have enough time to develop such an nexus for corrupt practices.