It's so cool when someone really groks on one of my lengthier ramblings-on. As Ernie added, the multiple parallel ground paths eventually have such a low total impedance, the entire installation becomes a ground mat.

Note: Electrical sub-stations are constructed over a copper mesh in the ground, to which all metal parts, even the fencing, are bonded. The idea is to assure that the earth surrounding electrical equipment is at the same potential as the equipment itself, even if not at 0 volts.

A couple of years ago, we did the entire in-ground installation for a cellular site; 5/8" copper ground rods (14), ground ring (#2 tinned solid copper), ground-rod connections and everything metal bonded by exo-thermic-welded connections throughout, etc.

We learned a lot on that one!

Larry
www.fineelectricco.com