You're kinda contradicting yourself. You're right that it's about absolute numbers. But then you use a percentage.
perhaps 12% for 5% of the global population is too high. But you dont want to relate it to population. Relating to number of countries is rather non-sensical. Some are big (by productivity, area, population, etc.), some are tiny.
Making it relative to countries is useful because that is the delination along which policy is made.
Making it relative to people, IMO, only serves to obscure the fact that the US/China/etc are by far the biggest producers of emissions.
Writing climate policy with them in mind makes more sense than pushing for somewhere like Monaco to reduce emissions, even if their emissions per person are high.