[cgenschwap]

You are right that maintaining documentation tends to be the sticking point. The main difference between a graph approach versus a tree approach is the _amount of effort_ required to maintain. If the documentation is incorrect in a tree-based system, say to the point where it is in the wrong place in the hierarchy, it requires a significant amount of effort to fix and maintain. In a graph-based approach it is easier to fix the areas that need to be fixed -- the maintenance burden is lower.

It is also easier to phase out certain documentation, but writing newer, more correct documentation and deprecating the old. Of course this is still possible with a tree-based solution, but there is more flexibility in a graph-based approach.