You indeed can have a two-tier system, but it is absolutely impossible that this would be 10-90. No, it would be 10-30-30 and non-existent(another 30).

This is the most stable advanced society you ever had. Present feudal systems exist only in agricultural countries where the elites have to travel around to get the proper luxuries of high status. Feudal lords in Guatamela, Honduras, el Salvador,etc... do have to travel around.. and they have to import the technics to sustain even the small non-luxury bubble they have to live in.

So, you can not sustain a luxury life with less than 30% of a properly trained workforce. And this is Argentina, Brazil and Chile 30 years ago... and one still could claim that the numbers were not that bad since the highly advanced luxury areas had better numbers, and that you had to take into account that large areas where dominated by feudal agriculture structures.

Just, think about the level of workforce that you need for the health structure, the computer structure, the research structure, the innovation structure to have more, exciting new things (more expensive than the other to get the status), the machinery use and the distribution, plus the high-quality food structure plus the chemist plants, plus the heavy industry knowledge...keep counting.. Brazil had all that in the 80's and it needed at least 30% of the population to control it. One could actually argue that, right now, you need more people.

The argument that a feudal system would need to be 10-30%-40% plus 20% neglected is that when rich feudal systems emerges in India, you will have to shift all the workers that are now helping to reduce the need for low-medium skilled works and some highly skilled jobs from supporting overseas operation to support local luxury.

The only possibility to get a new feudal system appears when the number of items to generate status is fixed, and you get a half a century of improvements in the production (better productivity) of these items... however , the present western totem mythology makes that impossible. Feudal lords will never accept a freeze totem-status system, it is just impossible to think. They will not accept the idea that there is no possible cure via research of the illness that will kill them eventually. While we keep in their heads the stupid idea that science can make their lifes longer and longer non-stop until becoming immortals, they will not even think of a mythology where new stuff is not important.

A pleasure

I therefore claim to show, not how men think in myths, but how myths operate in men's minds without their being aware of the fact. Levi-Strauss, Claude