One of the tricks to getring this working is to rethink how to run a campaign and how to balance it.
You will be a squad trying to take out a more powerful opponent, such as stopping a fleeing outer rim smuggler before they jump. As such, playing up the squad aspect might be the best idea. Imperials would be less about individual accolades, and more about the cohesive whole - the swarm. Treat the pilot skill as how the squadron operates as a whole. Now each player needs a reason to be unique, so earning upgrades and elite talents for surviving multiple missions is necessary.
To think of it another way; the empire will always replace lost pilots. But notable squad leaders such as Soontir Fel of the 181st aren't going to accept rookies straight from the academy; they'll get replacements of equal capability (in terms of pilot skill)
Perhaps earning upgrades for the whole squad could work. If you succeed on a mission, you unlock 1 hull upgrade for the squad. Any player can take this. If pilot abilities are earned for survival, such as Howlrunner's, etc.
This way, players can change loadout for each mission.
While requiring a purchase of a specific ship to run a campaign might not be great, having the gozanti function as a home base to protect during a mission could be interesting. It stores all your earned crew, modifications, and elite talent upgrades earned. Not to mention that TIEs dont have hyperdrives so need a way to get to each mission.
You would also need to have some missions that were more than just straight up combat. Scanning ships before they jump out to find the target, or which target has the mission macguffin and has to be destroyed.