to set the restriction on the user addition in the system, it will help the HR administrator to monitor their database as the system will restrict the key-in if exceeded than the subscribed numbers or can limit the exceed of how many numbers only. HR administrator has evolved a lot and minimize its' processing roles, therefore a good HR system should be able to assist the HR administrator to spend lesser time in monitoring the system but can rely on system to manage the necessary.
for the super admin role, it doesn't make sense to only allow the Super Admin to use the "User Admin" function to add and grant access to staff. commonly the Super Admin will be held by higher position in HR Dept and delegate certain rights to the HR staff for system access. but this Super Admin seems to be more busier than the HR staff to grant access and assign some settings for the staff. e.g. the HR staff is unable to assign the "Employment Status" to define the staff is full-time, part-time or any other status except for Super Admin. it is not effective to occupy the Super Admin's time to do such data key-in jobs.