Hello. What I've tried was to edit those player-sprite monsters (Lord Knight Seyren, High Priest Magaleta, etc). I replaced their body sprites with those jobs I wanted, then replaced their hair style, too.
Basically I don't need their blue-dark color effect so I tend to delete it, by the way.
The problem is, I found that there are a bit wrong and inaccurate positions set on their head and body after I replaced their sprites. This cost me a lot of time to adjust it one sprite by one, but I guess I was just editing it by a time-wasting way.
There's no default demi-human monster sprite like female knight, male crusader, etc, in the default grf. If there is, I guess the issue would be easy to be solved, cuz the position would be accurate.