So it turns out Starkiller has been orchestrating a lot more than previously thought. The Rebels attacked the Death Star and the Mandos attacked the rebels. Then Star Killer swooped in and attacked everyone. The players fled at the second sign of "trouble", namely Mandos that were as of yet unsure of what the teams were in this fight, but were glad to curb stomp the rebels. The players then retreated into the safety of their allies Imperial-Class Star Destroyer.
Then the players are told that the Mandos are following them and Star Killer is going to take them to beat up the emporer some. Also they have to go get the rebels to get into the fight too. So the players are stuck in the middle of the most carnage that can be caused by Star Killer's small force. Unfortunately for the players, the Mandos want them dead (specifically them), the Jedi are after them for betraying them, the Empire hates them and all Star Killers minions. Also Star Killer probably doesn't really care about them too much.