70% solutions: world-changing, but probably costly

In the book “Corps Business,” the author describes how the Marine Corps look for “70% solutions” – e.g. solutions solving 70% of any given problem. Having started at that baseline (which is similar in approach to the idea of the Minimum Viable Product), one can measure where inefficiencies are, iterate a test correction, and see if you can improve on the 70%.
Along that line, this morning I was thinking about what provinces and peoples form 70% of the remaining task. A quick and rough analysis of my Provinces spreadsheet gave me a list of 55. Unsurprisingly most are in India and China, with a handful of other places (e.g. Indonesia, Ethiopia, Turkey). The #1 largest province in the world is Uttar Pradesh. Change that, and it would make a dramatic difference in the world.
Having formed an initial list, the next thing I’m thinking about is this: of those provinces, which are positioned in such a way so that if they were dramatically transformed, they would ripple out into the provinces on their borders? In other words, what is the core of the core of the 55?
I theorize that the radical transformation of just a handful of places–probably no more than a dozen, maybe only eight or ten–would bring about a massive change in the world.
But to get to that transformation would likely be costly.