So i'm playing as the Sith Empire and im just observing the war between the republic and Mandalorians, but im heavily focused on buiding up my little side of the galaxy (korriban and surrounding planets/systems.)

Investing in economy and loyalty aswel as troops and loads of ships as much as I can and try not to invade too far into other territory, my question is cuz I got my borders locked pretty tight (and Malachor is in my backline locked) do I need to let the republic/mandalorians into that area in order to trigger the battle at malachor which is the final battle of their war in order to get Revan or is it like scripted and the moment one side wins I get Revan?

Cuz rn its gonna be tough for them to push through to Malachor as ive spent quite a bit of time reinforcing al my borders heavily.

Is it scripted or do I need to let go of some of the planets that give them a way towards Malachor?