that's not the point (but yes, i made the mistake of saying such, though that's not quite what I meant) what I mean is that richer people often live closer to the center of a city (better protection, better marketing, etc.) and often times, two things happen. First, as rich people are very protective and build small fences around their property and rather large buildings, it almost makes a large wall of buildings and fence systems, and the buildings being so packed together makes defense on their own. Also, likely the king will likely have walls built closest to him (the center of a town) and often times this will cause, even if not on purpose, the richer folk to be protected more. Also, in several kingdoms, and even governments today, the leading figurehead will take extra action to protect their best tax payers.

The point is, you'll likely have an area of a city/kingdom that is extremely well protected near the center, and the farther out you get, the less money is spent on protection and defense (especially when people likely will retreat to the castle keep in a time of danger.

Another note is that with an outer wall, sometimes one will have long extended walls that go straight out from the center of the city like rays from a sun, which allows roads to move alongside it and hinders an enemy attack, but they are often very simple and straight walls because such is easier to create.