So I just found out how henchmen are supposed to level up with the party. I am aware that you are supposed to hire them, then dismiss them, then have them join you again so that they get the experience. I have tested this with both of the companions (Madora and Jahan) and it works fine. My henchmen, however, do not gain any experience/levels when I do this. I even used one enough to level him up to level 2, then dismissed, then had him join again and that didn't work either.
Has anyone else experienced this? Anyone know how I can get them to level up with the party?