Wikimedia Statistics have a site map that presents you a list of all language editions of Wikipedia. You can sort them, for example, by “Participation: Editors (5+) per million speakers”. What will be the result?
The language editions who are on top of that list share one trait: They have a lot of ‘foreign helpers’. A foreign helper is someone who edits a Wikipedia language edition but who is not capable to write in that language.
Take Aragonese, quite high on that list, and have a look at Categoría:Usuario an. There is an impressive number of Wikipedians who indicate Aragonese (an) on their user page, but most of them have an-0, an-1 and an-2. They do not speak Aragonese or only to a limited extent.
Why do they have a user page on Aragonese Wikipedia then? Because they are from other regions of Spain but love Aragonese. Because they are Wikimedia activists who have to communicate to many language editions. Because they take photographs and put them into the articles in question, in all language editions where they exist.
Those people with an user page do not necessarily make five edits a month (= active user) but the trend is obvious: If a lot of your edits are made by foreign helpers then it seems that there are a lot of editors per million speakers. (The linguistic community being very small.)
Other language editions of this kind are Saterland Frisian (supported by Dutch Frisians) and Icelandic (supported by other Scandinavians). And, of course, most prominent is Volapük Wikipedia, a constructed language spoken by less than thirty people in the world.