The story doesn’t explain everything. Was it the place where the star passed over at midnight? On a certain day of the year? That changes with time, though. Need the New York Times for this kind of stuff, about the only thing they’re good for.
Also, over time the stars have changed position, even relative to each other. Polaris was not the North Star 2000+ years ago. I’ll have to check it to see if it makes a difference.
You’re missing the idea I think.
The stars, in relation to each other form a certain shape. The cities, in relation to the other cities, form the same shape. They aren’t laid out in any particular spot that has any relation to the stars, they are just laid out in relation to each other, to form a pattern that matches the stars.