The sequence of fields is determined in the country localisation.
The database table is this:
(Prefix_)address_format
For each country, the sequence of fields is put down there.
There are 244 countries registered, hence 244 entries that should potentially be modified.
I now realize that the problem as such doesn't really exist. I just happened to browse from the odd country which had the weirdest setup (in Indonesia localisation was made so that state would come before country, and that is rather the exception). Changed the sequence for test purposes and the change was immediately reflected in the form.
So normally, as far as geolocation works, the customer will see the sequence of fields that is set in this table, and which will usually make sense for the customer.
Table (prefix_)address_format contains only the country ID, so if you want to modify a specific country, you need to know the ID of that country (number between 1-244). To find out the number, browse table (prefix_)country where you can browse by country ID or phone prefix. Note the ID number, and go to that ID number in table (prefix_)address_format.
Problem didn't actually exist. Marked as solved.