Indeed, GerardM, I agree with you that a few good women or men with passions can kick start some Wikimedia projects, and different Wikimedia projects have different barriers or paths of development.
I also agree with you that the direction that I am pursuing may not be helpful to those languages in its incubation state. To be honest, I am not trying to measure the likelihood of success.
What I am trying to measure is probably akin to the external *difficulty* to be overcome for success. Here I have to admit that I approach this question wearing a researcher hat more so than a Wikipedian hat.
Having said that, I personally believe this approach can be very productive in generating outcomes for major world languages such as Mandarin, Spanish, Hindi, Arabic, Bengali, Russian, Japanese and Punjabi (all these languages have more native speakers than German, BTW). This way, researchers can make them more comparable because of the available external baselines.
I can envision that the outcomes can help these communities to find their strengths and weakness to develop. Then the strategies can be made to increase/expand their reach of available external content or users.
This should also help sociolinguists to identify which languages (especially non-national languages such as Kurdish or Cantonese) that are more developed than others in the Wikipedia sphere, and seeks explanations for their relative success/failure by contrasting the Wikipedia sphere and offline/online sphere. These languages include many of the mid-size language versions of Wikipedias such as Catalan, Cantonese, Tamil, etc.
Thus, I would argue that the analytical direction I want to take would be useful for many language versions which already have some user base and content. Again, I want them to be aware of both the internal and external state of each language versions, thereby contextualizing the differences among them. The baseline stats based on external sources should make them more comparable, instead of just number games among different language groups of Wikipedians.
Also, I have to agree with GerardM that the issue is both practical and political. I would like to add it is also political in terms of fund dissemination within the global Wikimedia/open knowledge movement. I personally believe that with the external numbers about potential available users and content outside Wikipedia, we can only realize how much is utilized/recruited from the external pool to the internal Wikimedia/Wikipedia projects. This should provide some sensible comparison bases on which Wikipedians can reflect upon.
Finally, may I point out the external environments for languages are also changing, which could be useful for the global Wikimedia/open knowledge movement. Based on my research on the competition of Baidu Baike and Chinese Wikiepdia in mainland China, I found that the windfall of fast growing internet users during the years of late 2005-2008 are crucial for any websites to thrive in mainland China, a windfall that Chinese Wikipedia missed because of the block by Beijing. From this, I argue that it makes strategic sense to catch the wave of rising internet users, esp. during the time when the penetration rates quickly rise from 12.8% to 40% for a given population. The external time-series data points can help pointing out the rising language users on the Web (probably Indian languages when Chinese languages have reached 40-50%).
Best,
han-teng liao