Yes it is indeed that part of the part screen. Where it says whether they are infantry, cavalry or archers you can also click and create a new group, such as 'Engles.' You could then leave this group at spawn when you start a battle, or even tell them to retreat, although I'm not sure if they still gain experience then. Also, putting them at the bottom of your party list greatly reduces the chance of them spawning in with you if you have a lot of men, thereby 'keeping them safe.'