Why should each individual party, some with so few members each, deserve a top-level subforum to themselves while all the Ministries, arguably the most important functional part of the region, are stuck under just one subforum? That's ridiculous.

People don't join parties because they see them on the front page of the forum, they join them because they're looking around for an appropriate party. In some sense, grouping them all together under one subforum helps with finding them. 

Top-level forums are prime space - beyond that they appear at first glance, they functionally allow quick skimming of the most recent topics in each subforum. Because of that, a subforum with lots of activity should really be at the top level and not clumped in with others, because otherwise it can obscure the other forums in its group. A subforum with a post every month is completely useless on the top level because it provides no new information to someone checking the most recent posts to see what's up.