I'm considering two alternatives for security groups. Mainly the Groups will be used in the Clubs and the objects the Club owns (like it's Forum). Each Club will have an Administrators group, a Moderators group and a Members group. But there will also be global Administrators and Moderators. Should I:

a) Add separate entries for Administrators and ClubX_Administrators (their permissions will be equal).
or
b) Add separate entries for ClubX_Administrators and add Administrators as a child Group?

Alternative b should result in less data, but will it give better performance? Are there any drawbacks? Does it matter at all?