Pretty much every group of any size is going to have splinter groups within it. Those that might have the same overall goal in mind, but go about it in slightly different ways. It's looking at these different sub-factions that Games Workshop does in their preview of the upcoming Daughters of Khaine battletome for Age of Sigmar.
From the post:
The new Daughters of Khaine battletome is up for pre-order this weekend. With it comes a variety of ways your servants of Morathi can spill the blood of all who stand against them, and as you would expect, the battletome features a plethora of suitably bloodthirsty allegiance abilities. In today’s preview, we’re looking at some of the sub-faction rules in closer detail.