by dedindahed
Taking an empty home realm hex does count as a battle, it was mentioned in the rulings from corey document.The main reason for this is to prevent you marching through 2 empty home areas, or one occupied area and then an empty home area using the mobilize order card.
I think you may also draw cards for battle if you desire when taking an empty home realm (necromancers, daquan knights spring to mind)
The big difference between empty home and non-home regions is that one is enemy controlled and the other is not.