Full Idea
Many philosophers say that one cannot intelligibly subscribe to the reality of relations unless one is also committed to the fact of some things that are related.
Gist of Idea
A belief in relations must be a belief in things that are related
Source
J Ladyman / D Ross (Every Thing Must Go [2007], 3.5)
Book Reference
Ladyman,J/Ross,D: 'Every Thing Must Go' [OUP 2007], p.154
A Reaction
Ladyman and Ross try to argue against this view, but the idea makes a strong impression on me. Your ontology seems to be rather strange if you have a set of structural relations that await things to slot into the structure.