I would technically think of these two things as entirely different functions. The key elements of configuration management include the identification, labeling, control, status accounting, and auditing of changes. The change control system is a related function in that it determine what changes will be put through the CM process and which will be tabled.
The question of duplication of effort is an interesting one. In general, duplication of effort may come from several sources. One would be a weaker change control system which allows duplicates through the process. Another would be a configuration management process which does not have a robust means of identifying changes and inspecting them for related activities already in the project pipeline. Still another source of duplication of effort may be project resources that are not working efficiently.
In general, duplication of effort will have an effect on the efficiency and effectiveness of an organization or project. The CM and CCS processes may need to be reviewed and strengthened. In addition, the project manager needs to be aware of how work is being carried out. For example, on a software project, are the developers re-using code or re-writing/developing code.