Bashed Patches created using CBash do not correctly merge in face data, hair or eye changes. Relevant posts:
http://forums.bethsoft.com/topic/1369624-relz-wrye-bash/pageviewfindpostp20755754
http://forums.bethsoft.com/topic/1369624-relz-wrye-bash/pageviewfindpostp20758213
This is likely specific to the NPCFacesForceFullImport tag. I make heavy use of the other one, NpcFaces, and it correctly imports everything in CBash.
This behavior doesn't seem to be specific to the NPCFacesForceFullImport tag, although it does seem to be related to more than one mod with the NoMerge tag touching the same NPC record, even if they're touching completely different subrecords. Please see http://forums.bethsoft.com/topic/1402777-relz-wrye-bash-thread-94/pageviewfindpostp21542677 for more details.