The Idea: A planetary system composed of many interconnected nodes and small bodies in a semi-stable arrangement, with much shorter distances between astronomical bodies than our own Solar System. It's kind of like an orbiting structure made of tinker toys, or the floating mountains in Avatar on an astronomical scale.
Take this, but scale it up. Individual planetoids/rocks in this system should be able to see other bodies, with something like the distance between our Earth and Moon as a common range. So with a much greater density than the asteroid belt, and fewer collisions than a planetary ring. A star still forms in this structure, providing a chance of life evolving on these planetoids.
The Explanation: Our planetary system forms with a significant volume of exotic matter; let's call it Zero-Mat. This particular exotic matter has an interesting property: it repels itself, but increases the gravitation pull of any regular matter near it. It's influence falls off much faster than gravity, say something like 1/r4 instead of gravity's 1/r2. Thus these exotic particles could attract matter to themselves, but keep that matter from aggregating into larger planets. There may be some mechanism/structure of the exotic matter that allows it to bind together, like an alien form of the nuclear force, if the repellent force is overcome.
The Question: Would this explanation in any way work? Would it allow this proposed system to come into being?
What other ways could this system form?