Hotline, I really try to dodge "what is the code minimum" type of question .... if for no other reason that Article 90 tells us not to use the NEC as a design manual. Naturally, when I point this out, someone will reply "but Article 90 is not an enforceable part of the NEC."
Another reason is that there are very few times a 'one rule fits all' practice actually does fit all! Add to that the continuing influence of other codes (ICC, UFC, etc.) and a simple NEC answer might be incorrect. For example, the Fire Department might want a shunt trip for the entire building, regardless of how many meters there are.
