So, y'know what... maybe there ARE balanced star systems out there. Oh wait. For example, ours.
The Earth is balanced by the moon's orbit. Now, there's no "equal threes" going on that we know of, but how does balance work?
A small object can balance a larger object if their mass is similar or the same.
A lower mass object can balance a greater mass object if their distances from their common fulcrum are different, giving the lower mass object a leverage advantage. Or in the case of celestial bodies, giving the lower mass object a leverage or orbit advantage even in spite of its smaller gravitational forces. This is why the moon has neither crashed into nor drifted away from the Earth, even after millions of years of this seemingly eternal waltz they're engaged in.
There could be binary systems, such as the Earth and Moon, which are part of a larger binary system such as Earth & Moon together in opposition to Sol. Or maybe this is just a lopsided trinary system that has found a way to balance itself even though the participants couldn't be more different.
Could there be trinary systems that are somewhat more homogenous in nature? Sure, and maybe those would be more likely to balance if the individual elements are equal in size, mass, and orbit characteristics.
If there could be trinary systems, then why not double-trinary or triple-trinary systems?
I'm not proposing that we should have a lot of these in the game, but I am proposing that such celestial formations might not be all that crazy or mathematically rare, especially since this game is played only in two dimensions.