Just to clarify, "SA" does not ally with anyone. Individual realms have chosen to ally with Terran, and, so I hear, send troops around. But unless you hear an announcement from the church, then the people doing it are not "SA". This is an important distnction, not an empty semantic exercise.
Sure. But in practise, seems like almost every SA realm in jumping in. Except maybe Kabrinskia, but fighting alongside them would be extremely awkward anyways.