Happy New Year everybody!
MMH55_Editor_64_NCF.exe is used only to manually edit NCF monsters. ARMG does not work and will break every time.
If you want to generate a map first uninstall NCF modules (open the NCF utility and click Purge) then open MMH55_editor_64.exe and generate what you want.
Deploy NCF again, use mapmixer on the map, play the map.
You spotted only one NCF monster because the frequency at which MapMixer places them is low.
All NCFs are neutral so make sure to increase the Neutral stack frequency to max (4) as shown on the picture below. Let me know how it goes
Thank you for the feedback!
P.S.
Missed the camp question. ARMG can place mixed stacks which makes the battles more difficult. Usually almost all of the adventure map NPC stacks are mixed.