I got my "factions" example up and working and can easily create new factions and alter the existing ones via the editor. (As seen in this video).
...and then it hit me!
SCRIPTABLEOBJECTS ARE FOR READONLY DATA!
Sadly it wasn't until I actually got my example to update an existing faction that it hit me. All scriptableobjects are stored in the READONLY bundle. FFS!, what an idgett!
EDIT: They are of course still very useful in reducing memory as described HERE.