I'll concede that it's impossible to know how many words are in a language.

However, wouldn't it be possible to get a count of words included in all types of dictionaries in given language? That would exclude languages that don't have a sophisticated array of dictionaries, but at least you could compare words listed in dictionaries.

I have no idea on which sources the articles I read were based. I would think there is some huge data base somewhere that lists all words appearing in dictionaries in any given language. It would be a huge task to create such a data base, but perhaps one exists...somewhere.