Yeah, that's fine~ I don't have any specific enemy groups set up off of Promethia, but wars and the like are still commonplace enough. Pirates are a big problem past the border planets, and depending on the group could be ex-military. As for crash landing, that's how a lot of people end up stranded there! Totally workable. If you don't like space pirates, there are a few alien races that are hostile to the as of yet unnamed galactic government of this particular arm of the Milky Way, they're always waiting for some bullets in their heads/cephalothoraxes

And you can definitely have a reserve!