There is much to consider on this topic. Regarding permanent ministries, @Welly and I briefly discussed this in my PM campaign thread. I will copy my response from that discussion here, as I believe it may be relevant to this conversation.
Expanding upon that, while the idea of establishing certain permanent ministries may provide stability in core governmental functions, imposing strict limits on the Prime Minister’s ability to create additional ministries is an unnecessary and harmful constraint. The Prime Minister must have broad discretion to shape their government, ensuring that ministries align with their policy agenda and the evolving needs of the region. Locking the executive branch into a rigid structure of fixed ministries would hinder responsiveness to emerging challenges and policy shifts. I think the proposal rightly acknowledges that, if permanent ministries are established, their ministers should be appointed by the Prime Minister rather than directly elected. A reasonable compromise, therefore, would be to enshrine the ministries listed in the proposal while preserving the Prime Minister’s power to create and dissolve additional ministries as needed. I don’t see any good reason reason to limit the Prime Minister to two additional ministers without a portfolio.
The mixing of terminology in this context is rather confusing. We should adopt a consistent terminology and refer to these executive bodies either as ministries or departments, rather than having permanent departments subordinate to ministries. I would argue in favor of “ministries,” as this is the established terminology currently used in TSP. Moreover, I think it would be better in this case, to establish a permanent Ministry of Foreign Affairs and a permanent Ministry of World Assembly Legislation, though I would personally rather include the latter in the former. In my opinion, there is no compelling reason to change the existing terminology.