Since I did not use zombie master, which seems the main reason to use the necromancer, switching to the liche was simple for me.
I had a highly upgraded necro, and the liche is a better container for him.
Thank you both for your answers. My instinct went with the “They are not undead” because being a human and a leader. In my game they got charged by a Knight Champion and lost two combats but did not die. WE ruled a break but no route. Had it been a route, that is a different game for sure.
These kind of rule interactions are a part of the game I enjoy, so thank you both for the help.