Well, the first few seasons have some good development for Ventress, which leads nicely into the Maul content. And the Anakin/Ahsoka relationship, which also develops on Mandalore.
The major arcs beyond that which usually get moviefied are often major battles, but these don’t always have a valuable emotional core. So I think defining the arcs on those major metrics- Vital, optional, skippable, and great-but-not-vital, is going to be important.