I'm still just somehow trying to figure out if the shape of the ruins has something to do with the others' planets and positions in them, but I'm getting closer and closer to just concluding that whole thing is just nonsense. It's slightly less frustrating than flying blindly around random beige colored deserts for hours.
Here's how I see the bloody thing:
It has 2 major circular elevated structures that seem to be joined by the lines of the hexagon. I could assume from the way the structure is presented that it refers to a binary system (star, or planetary) where one of the bodies is much smaller than the other. Binary planetary systems exist in all 4 of the suspect star systems, and for example the ZL-J system has a few Gas Giant / Iceball binaries with that major size difference. Binary stars can be found within 3 of them, the exception being the ZL-J system. Both circular structures have a extra broken "rings" around them, which could possibly point to a planetary ring. All this would initially lead me to believe that moons of planets 7, 9 and 14 might be valuable candidates.
But then there's everything else in the structure. The relic locations look like they may have some correlation to the galactic map, but it's likely just coincidence. The hexagonal area has two elevated flat platforms in the top left and center right, neither of which seem to bear any significance. The large circle has a line pointing "down" at bearing 155°, with a little bit coming out of it to the left, again of no known significance. The smaller circle has a "bay" outside of the main hexagonal area, once again seemingly for merely aesthetic reasons. There's also an elevated area to the left of the large circle outside of the hexagonal area that houses the "G" cluster of obelisks. No idea what that's supposed to mean. To the large circle's right there's a flat area containing one of the relics, and the whole thing concludes with 2 pyramid-like structures, one inside and one outside the hexagon.
And all of that is just utter nonsense. Especially with the information that there are numerous ruins, I just can't see how the ruins offer any actual clues whatsoever to where the other sites may be found. It's basically just caveman scrawlings.
The Guardians were idiots. They all just got lost in space because none of them could find their own colonies.