And what if we leave the national teams as they are? What if a merge only meant that you'd be playing league and cup games against the managers from other Scandinavian countries for added competition? Do you have a problem with that?
This seems to be the clear choice in the national forum merge threads of Norway and Denmark. Iceland just have a few active teams, with one comment that prefer option 1, but I don't know if they have followed the global discussion with all the small changes and suggestions. Sweden and Finland is currently not included in the suggestion. I propose that you will consider asking their communities if they would like a merge of the Scandinavian/Nordic countries on those premises.
I think it is the best solution, since the point of keeping the NTs are a big factor for many. We would get a league of about 450 teams. A good size that can sustain some loss of teams and also have room for growth.