I don't understand a thing about ground resistance.
Let's say that the power plant servicing my house is placed at a distance of 100 meters from it. If we hypothesize a resistivity of 100 Ω*m, the overall ground resistance seen from my house should be:
Rg = 100 * 100 + (Cable resistance + earth stake resistance)
If the above formula is right, we get for Rg a value of (10000+20)Ω. The problem is that with a ground resistance this high the grounding isn't much helpful. With a resistance of 10200 Ω a human touching a grounded chassis will take all the current.
My question is: how can an installation with such a high ground resistance be able to protect the user?