It can be confusing enough for new players when they have a Chancellor, a Minister of the Interior, a High Poobah, and a Lord Marshal. Trying to figure out what a Legatus and Centurion, a First Dan and Second Dan, or a Hordeleader and Warchief are just make it that much more confusing and annoying for them.
There's a reason we don't allow total customization of all realm titles.