Well...... IMHO and all that......
The NESC is a good safety code for distribution and transmission, any utilities on-site will use that.
It's probably a good safety code for everything involved.
Any utilization equipment and wiring will need the NEC.
A lot will depend on the AHJ and their interpretations of where the two codes cross.
That’s rich. I have never seen a utility pull permits except new construction. I’ve personally pulled permits for an industrial twice in 30 years, playing NJ politics. Both are effectively permanently under construction. Something is always being modified somewhere.
And if you call the AHJ and ask them when NESC, NEC, RUS, and OSHA all disagree, you will just make their heads explode. Out of all of these the only ones likely to inspect are OSHA and NERC. I’d love to see the local Code inspector get into it with OSHA. Wonder who wins that fur fight?