One possible model of where this could head: Wikisource's ribbon system for indicating degree of proof-reading. Basically this is a traffic-light colour code. Pages that draw on several pages of an original book may be a mixture of text that is unproofed (red/pink), text that has been proof-read once (amber/yellow), and text that has been validated by a second proof-reader (green).
A Wikipedia page system has to take account of more and disparate factors, if it is based on the sort of mechanical processing under discussion. As I described, certain things would "raise a flag". For example, if the footer sections weren't in the standard order per the manual, that would be a low-level indicator of possible neglect. On the other hand a WikiProject rating, if present, is better news: someone apparently cares.
Rather than try to render different straws in the wind down into a single score, this kind of ribbon system would keep several dimensions going.