Any flight surface has an upper and lower balance limit. When they are balanced off the aircraft as per a jig method, the idea is to balance it as close to the lower limit and then fitted.
This will allow you a bit of room to add weight to the surface i.e. painting or repairs, without adding balance weights, during the calculation method.
The rudder on the 747 is hydraulically actuated and not required to be balanced. Dampers in the system reduce any flutter, which is the main reason for balancing. This holds true with most any hydraulically controlled flight surface.
As far as I am aware every flight surface is balanced as per the SRM, and the dampers in the system are mainly used to prevent the surface knocking around in the wind when the hydraulics aren't pressurized
If it's not broken, don't fix it !