If I were to run an Age of Rebellion campaign, I would want to pitch it during the Clone Wars rather than the Galactic Civil War. The clones are incredibly rich characters and ripe for roleplaying.
Stranded on an Abandoned Planet
There would be room for 3-5 PCs in the campaign. One would be a Jedi padawan and the others would be clone troopers. The game would kick off after their ship is shot down during a disastrous Republic assault on a Separatist world. They are the lone survivors of a repelled invasion force. The padawan’s Jedi master has been killed. The squad’s CO died in the crash. They are alone.
Now the squad is trapped behind enemy lines and presumed dead. They must find a way to survive and escape the planet. Or perhaps they decide to complete the mission their battalion was sent to accomplish, now against impossible odds.
A Bit of Spin
Characters would be straight out of Age of Rebellion. The clones would all be human and could be any Career and Specialization in the book. The padawan would be out of Force & Destiny, with 75 additional XP. It’s not enough to reach knight level play (as outlined in the GM’s screen supplement) but it’s enough to invest in some Force powers.
The spin comes in from 13th Age. I’d give each character One Unique Thing. It’s a great bit of tech and can lead to some incredible roleplay. The hope here is that the characters would do fun, interesting things like the Bad Batch. My dwarf monk in the 13th Age game I’ve been playing has the One Unique Thing of “First dwarf born of stone in Ages.” It’s been great fodder for plot hooks, Icon relationships, and characterization. Like 13th Age, it would be a narrative tool but I may throw in a bit of a mechanical hack where players can spend a light side Destiny Point to do something cool related to their One Unique Thing.