First, be clear on one thing: no one truly 'understands' electricity. ALL of our models have flaws, and 'unusual' situations usually underscore the weakensses of our models.
I am a strong supporter of transfer-switched neutrals specifically because of questions like these. I'd rather avoid the uncertainty.
Here's grounding in a nutshell: Electricity only wants to "go home." It does not want to go anywhere else.
For power from the power company, this means it wants to go back to the transformer that made it.
For generator-made power, this means it wants to get back to the generator.
For lightning, this means back to the planet surface.
The 'neutral' is nothing but a path 'home.'
Care to guess where the ground rod fits into all of this?
