I'm having trouble figuring out how the MNSF (Max Number of Sustainable Facilities per city) works. From the name, it seems to imply that each city has a maximum number of income facilities allowed since it says per city.
However, when it talks about RNF (real number of faciliteis), it states that it is the "# of facilities of each specific type of facility that is on that planet".
The rules add more confusion by stating that "There are some business where there is a limited demand for their services for a given planet or city."
So, if I build four hotels on my city slab, and my neighbor builds 50 hotels, is the income divided up between all 54 hotels? Or is my city's half divided up between my four hotels, and my neighbor's half is divided up between his 50 hotels?
To put it another way, is my neighbor's 50 hotels leaching money away from my four hotels?
Indeed, its based on the whole planet. Some facilities such as the cathedral actually have fractional MSNFs, and as far as I am aware you cannot build 1/4 or so of a cathedral, so you have to make sure there is only one per 4 cities for example to get max income (I'm not saying it is 0.25 per city, just as an example).
One of the reasons FI planets are generally tightly controlled, even when a faction lets their members and others build on their planets, to avoid too much income being lost.