It is very much ordered that way on purpose. Opposites on the chart means opposite Nature. The further apart the more opposed. Those on the same branch as one another share some common thread as well.
For Instance:
Water & Fire are opposite one another, as are Shadow & Sun along the same branches. Fire & Sun share a link in their heat and turmoil. Shadow & Water share a link in their coolness and deception (when you reach into the water to try and grab a fish for example. Where you see the fish and where it REALLY is are two different things).
Law, Mind & Force share the common link of Control & Connection, and stand opposed to Chaos, Enchantment & Dimensional, which share the common link of seperation & the Unknown.
And at the center is Metamagic, which is to represent a Harmony & Connection of all things.