In such case all of these should be listed, so you know where are these resources from. Currently UI tells you control 6 of 5 pieces. You look at the map and see only 4 and 1 unimproved. What the hell? Then it turns out you have EIC adding 2 extra that are not mentioned in the monopoly window. This is true for every extra source. People like me, who learn some things should have this info shown. I don't know why it is hidden.just noting the example in the OP isn't quite correct. If Person 1 has a monopoly, and then person 2 gets a higher % by building east india, ONLY player 2 gets teh monopoly (player 1 loses it).
Personally I would rather we go the opposite direction. Allow multiple people to get monopolies, and then no extras affect the map, it is purely map driven.
Ie if the map has 5 copies of a lux. If I have 3 copies, I get a monopoly. If the next person had 2 copies out of 5, no monopoly. They get east india, they now have 4 copies (but still out of 5). Both players get the monopoly.
And before the thematics people come down in that, in real life a monopoly is often not control by just a single entity, even a small number of companies can often utilize "monopolistic" practices, so allowing for 2 civs to share a monopoly is not crazy to me.
EIC is easy. But when you add up other factors like policies, beliefs and UAs, then it gets funny.