250-53 A grounding electrode conductor shall be used to connect the equipment grounding conductors, the service equipment enclosures, and, where the system is grounded, the grounded service conductor to the grounding electrode.
250-21a The grounding of electric systems, circuit conductors, surge arresters and conductive noncurrent-carrying materials and equipment shall be installed and arranged in a manner that will prevent an objectionable flow of current over the grounding conductors or grounding paths.
250-21c Temporary currents not classified and objectionable currents. Temporary currents resulting from accidental condition, such as ground fault currents that occur only while the grounding conductors are performing their intended protective functions hsall not be classified as objecctionalbe current for the purposes specified in 250-21 a and b above.
If I read this right, there should be one grounding conductor with a single bond from equipment to it. An arrangement that parallels grounded conductors, one inside the box and one outside the box would allow normal load currrent to flow outside the box and therefore be objectionable current. For illustration, connect the grounding conductor to the service neutral at the service entrance, connect the service neutral in the disconnect to the grounding conductor and also from the service neutral in the meter base to the grounding conductor. I do find where the transformer outside the building is to have a separate ground but these would be separated through say 40' to 150' of soil. The service equipment is located in one place. I only see grounding conductor and attachment used as singular terms never plural. Where is the reference to multiple connections to ground?
