To be sure, this is to large a discussion. As a method for spreading development increasing amount of regions and cutting some down some large can be good.

Switzerland where I live very much has this, with 26 top level provinces and only some 8 million there is and a crazy amount of localism, mostly only have 100k people. Each with their own school systems, their own tax polices and almost everything else too. That is of course because of a history of slowly growing together with many compromises (and a civil war thought about the issue of centralization in 1847).

Most former colonial powers preferred to set up provinces as that requires less people to administer and control, and nobody cares about the hinterlands anyway, as long as there weren't major resources there.

So I think this is a good policy. But system do need to be in place to make sure these areas work together on things like transport policy. This is still a major struggle here.