I revert back to the OP and answering that without muddying up the waters and making a simple answer complicated.
as I refered to in my previous post unless there is a spec that must be complied with how much messing around does one have to go through in order to meet some unknown requirement?
I am in total agreement with you regarding actual bonding and tripping breakers. I wanted to make a point that if grounding resistance is thought to be important because of being able to trip a breaker should there be a L-G fault that those who believed that would be way off target. The NEC has come a very long ways in the past 30 years and I would like to think that if the NEC requirements for grounding were not sufficient enough that it would have been addressed by now in the code reviews by addressing something more that (2) ground rods.
Look at how many times Article 250 was totally re-written. The subject of grounding almost always results in some sort of disagreement. It's like that in radio, too. Worse, actually.
The first code books actually forbid grounding a current carrying conductor. Then, around the turn of the 20th century, it required a current carrying conductor to be grounded. Just since I have been in the trade we have went from one rod to two rods to connecting to re-bar as a requirement for new installations.
Remember, the purpose of the NEC is not to aid in design. It is a bare minimum set of standards resulting from compromises.
If you want a better connection to the earth, by all means go for it. The NEC does not forbid that. If you want to see what an effective grounding system consists of, check out what they are doing at cell sites. They can operate flawlessly whilst taking direct lightning hits. The lightning protection system on a cell tower costs almost as much as the tower.
As an extra class amateur radio operator that teaches classes, the subject of grounding for protection often comes up. Some feel that there is no way to design a system that will take direct hits without damage, as lightning is mother nature and does what she wants. The fact is that a system can be made, but will be prohibitively expensive.
So, where should we put the requirement? Should we require every home owner to have a lightning proof system? (Which would cost more than their house).
Or do we just drop the grounding requirement?
As I mentioned before, the NEC is a compromise and the result will fall somewhere between perfect and useless, and since the NEC is a bare minimum standard, it will be skewed way toward the useless side. IMHO.
Testing for ground resistance and knowing how to do it properly is just one skill. That skill may never be needed. Knowing how to use a Hi-Pot correctly and properly graph the results is another skill that most of us will never use. Heck, most of the guys I see post on this forum use a 'Megger' like a DVOM and probably have never done charted readings, or know what the readings are telling us. That's fine. Someday they may need to do charted insulation testing and at least will know how to operate the 'Megger'.
It is far better NOT to rely on the NEC for instruction and, instead, learn about any subject covered by the NEC from a source meant to educate, not regulate.
So far, Mike Holt's forum has been running neck and neck with my books for the acquisition of electrical knowledge. I have all of them from my apprenticeship plus shelves full from automotive, marine and heavy equipment electrical systems books. And theory and physics. But this forum has something the books don't. That is the ability to communicate with people in our trade that we would NEVER be able to do otherwise.
Using the NEC to try to understand our trade is like using CFR 47 Part 97 to try to understand amateur radio.
