don't know if you're still looking, but did you remove the shadowing lines in british_isles/data/dsec_sm_factions eg:

faction england, shadowed_by barons_alliance
and
faction barons_alliance, shadowing england

you'd need to have unpacked the files to get to that file and be running with the file _first command for it to take effect, would also need you to restart campaign. Deleting the map.rwm file might be safest too.