Many-to-one

[vosreth]

Could you give an example of encoding anything at all this way? Say "this book is about plants and stars"

The system can't encode that sentence and the reason it can't is the point. It has no open-class vocabulary, no word for "book", "plants" or "stars". It has no conjunction ("and"). You'd need illustrations, section placement, and page position to provide the semantic content. It's only telling how things relate to each other. 

Something close to "this book is about plants and stars" could be qokedy daiin daiin, but you'd only know what the referents are from the context.
"This definite thing does. Acts-upon-[referent]. Acts-upon-[referent]."

"Why would anyone, and especially multiple scribes, invent a system like this" is one of the strongest objections anyone could raise, and I should have addressed it in the original post. Consider: musical notation, chemical formulas, tabular astronomical records are all systems where multiple hands record structured information using a shared formal vocabulary. Nobody asks why multiple scribes would use the same notation for planetary positions. You invent a system like this not for writing but for recording. The notation is the point.