The only possibility to train your followers is with the "educator" background; if I understood correctly you are able to train your followers one up to one level below your own character, e.g. you can train a npc as an apprentice in firearms when you're an expert - hope that's correct!
Yup, if you have this background (educator I think), npc's will automaticly gain levels in the categories you are trained.
They can become expert(assuming you master the skill yourself), but you can never teach them the master rank of anything.
Sorry about that. Suppose to answer that while I was thinking of the answer for that other question. Thanks for the correction. :razz: