Earlier quoted context omitted.
Perhaps there could be a ranking that takes posting frequency into account, and lets people decide whether they want to see higher- or lower-volume blogs. Perhaps not a straight ascending or descending by frequency. For me, the sweet spot seems to be no more than once a month. More if it's one that does something like a weekly post aggregating interesting articles from other blogs.
Why would you penalize a blog with 3 authors who publish 3x the articles of a personal blog? Why would you penalize higher volume at all? Trying to ascribe anything close to quality based on volume is like trying to grade developer productivity and/or skill by LOC.
I'd possibly put a shared blog under a similar category as the ones with weekly roundups. Which is exactly why I threw out that example - I don't want hard-and-fast Google-style rules, because I would expect that to work out about as well as hard-and-fast Google-style rules ever does.