This sort of registry set agrees with my kind of collecting philosophy.

It is my aim to try to attempt to build a collection that represents the development of all coinages around the World in all cultures, since the invention of coinage.
Obviously, such a collection is impossible to complete (that's OK), but I have been actively been at it for the last 30 or 40 years,
Nevertheless, as the collection now stands, it already tells a fairly reasonable numismatic narrative.
Along the way, I have learnt an enormous about World cultures, their economic development, and why they declined and faded out.
All illustrated by their coinage hardware.
My collection in most cases not quite up the the condition standards of the
NGC registry set.
However, it currently comprises about 500 coins, and includes at least one example of a representative coin from each major World culture, and in most cases, multiples in all three metals.
Modern machine made coins after about 1800 comprise about half of the collection. That is to be expected, as World populations grow, along with their economic activity.