Good Day, I have observed this problem as well during my Mod development efforts. This issue can be re-mediated by simply editing the packages for the NPCs that use use under your Mod. For example under one instance, a group of pirates came out of no where and began attaching my main NPC. I troubleshooting this issue down to an orphaned package that I had used for other NPCs. So the best practice is, insure that any packages that you borrow from other NPCs or creatures, insure that you give them an unique object ID. Regards, KWITS