Is it legally unwise to have separate attendance policies for separate departments?

Q: “At our agency, each department has its own attendance guidelines when applying and waiving attendance points. The agency is in the process of reviewing each separate departmental guideline for attendance to develop one set of administrative standard operating guidelines for the agency. Should the agency continue to allow each department to operate under individual attendance guidelines? Or should Human Resources develop an agency-wide attendance policy, where all divisions follow the same guidelines? If the agency continues with each department having separate attendance guidelines for applying and waiving points, will it be viewed as discriminatory?” – Anonymous, Virginia