I fear (a big word) that regional subgroups would not only discuss very local topics, which would be ok, but also would keep themselves off the `majorī group making a parallel forum.
The appearance of Apug, as I put it, could be changed in a way that it rather becomes a bundle of groups doing their own discussions. Instead of what it currently is: a Forum of people from all (read: many) parts of the world bringing in their different expertise an curiosity on different topics.
There is that language barrier, and a subgroup of its own language would not neccessarily make members of that group post in English. Rather the opposite.