To distinguish between the two types of cemetery you described I would in fact use a cemetery=* tag and as there is no value for this tag which would fit your purpose you should feel free to create your own. Why not use the descriptions “ordered” and “disordered” for this purpose. I don’t know if there is anything like this in other countries, but it seems quite unique to me, so it could be wise to include the country code to make clear that this tag is specially used for North Korea. I could imagine something like cemetery=KP:disordered.
Btw: Great work you did with your guide for contributions in KP … I take off my hat … 