Hi, only here to correct some info about Astrologian.
The 20y listed on Macrocosmos is not the circle span (diameter), that is the radius starting from you. Therefore Macrocosmos has a diameter of 40y (i.e. longest distance within the circle) with you as the center.
To explain the significance between 10y and 20y radius, here the surface area of those circles.
Formula: r² * π(pi) = ? y² (square yalms)
- (10)² * π = 314.1 y² (100% base)
- (20)² * π = 1256.6 y² (400% relative)
So a 10y radius circle only has a quarter of the surface area of a 20y radius circle.