I have a type of henchman that I call Admin. It has the Veteran attribute so when my Fortress has Command Post, I can train a Commander with Administrator I, Administrator II, and Road Building.
Twice today after I had selected 'Commander', the second step only showed 'General' and did not show 'Commander'. But then the third and fourth steps did show 'Commander'.
Note: I use these to reduce unrest with the side benefit of road building.