It would be much easier to try help you if there would be load order.
Faction mods are definitely working, using them by myself currently, so most likely it is conflict between mods.
I know well, that NPC overhaul conflicts with FCO mod often, but you are not using that?
Try to put dragbody overhauls in the end of your mod list and check out once again, if they started to work. Also check out original topics of overhauls and comments below them. There were also few questions about same subject on other websites, try out Google.
There are also few similar topics about that in here, just look below - it shows "similar" topics.