SYSTEM account in SHARE permissions

I use a standard list for share permissions on our 34+ servers. Each office location has an operators account “OP1” and a group account “PITUSERS”. The permissions are as follows:

Domain Admins: FULL CONTROL
OP1: FULL CONTROL
PITUSERS: CHANGE

Note that the EVERYONE group is removed. Other NT admins have told me that I need to add the SYSTEM account with full control if I remove the EVERYONE group.

I am not having any problems – that I know of. What ramifications will I have by not adding the SYSTEM account? Should I add the SYSTEM account?