Is there a reason you haven’t allowed any of the other playbooks? AFAIK SW and M are the only required ones. You can use any other ones you want…

As mentioned in comments on the other post: I actually think SWvM is actually a great option for a rotating cast. The canvas is so vast and epic you totally should be able to have different story lines going with different groups of characters as long as you are willing to stagger them a bit vis-a-vis timeline. If you can get consistent attendence from your SW and M players I think you could just have M team up with different groups to fight different fights against SW. If you can’t get those players consistently I think you could totally just more massively time-shift and have SW and M be immortal aspects of sorts… Is that crazy?