In this blogger's opinion the Part 15 Rules are sketchy.
They lay out a model scenario; a general situation; a typical setup.
But the Part 15 Rules do not attempt to anticipate the infinite possible situations that might arise, and therefore must be applied creatively.
Let's start with the known, and work our way outward from there.
At your house the Rules allow an AM transmitter with 3-meter antenna, 100mW to the input of the final RF stage. A well worn fact. Such a transmitter, if well installed, might reach 1,000-feet or better.
Suppose in four other blocks, east, west, north and south of your home, you owned other homes. A total of five homes.
Each of those homes would qualify for yet more of the same type Part 15 AM installations.
Suppose you consolidated these into a single, centrally located system.
You would be entitled to 500mW to the final RF stage and 15-meters of antenna.
Yes, it does.
That illustrates the intent of the Part 15 Rules.