Admin role is very similar to staff (see exceptions below) but their access is based around schools.
A SysAdmin user needs to set up an 'Admin' account and then assign one or more schools. The 'Admin' user can access any paper/question attached to any module in the relevant school - they don't have to be explicitly added to all the modules.
Exceptions
Admin users can create new user's accounts. Admin users can manage a users accessibility settings