I personally think it's a cool idea, but probably a bit below the scope of this game... remember, you're going to have empires with hundreds or thousands of ships here, do you really want to track every single crewman on every single ship?
Now maybe if you could track different kinds of experience for each ship's crew, and transfer crews between ships... in other words, instead of "Executor 0001 is at 5% experience", you could have "Executor 0001 has 1562 crewmen with 10% in gunnery experience, 7% in tactical experience, 2% in scientific/exploration experience, 6% in engineering/repair experience, and 3% in medical experience. The ship requires 1500 crew to operate at optimal capacity and has quarters for up to 3000.", and if you wanted to transfer more experienced crew from the Eggsterminator 0002 (what a silly name for a ship
) then the relative experience levels would change based on how many crew you transfer - if you transfer a lot of crew, the experience changes a lot, but if you only transfer a few, it only changes a little. (So it would require a lot of 60-man Escorts to replace the crew of a 3000-man Dreadnought
) See the BBS game "Falcon's Eye" (not the Nethack front-end, the BBS multiplayer strategy game!) for a good example of handling aggregate experience; you have experience Ratings from 5 to 10, 5 being the default that people get when they change occupation. Let's say you have 100 builders, and you want to make them mages, but you already have 50 mages at rating 10. So your builders become mages with rating 5, but they're averaged in with the existing mages, so you have 100 * 5 = 500 XP from the builders, and 50 * 10 = 500 XP from the existing mages. You have a total of 1000 XP divided across 150 people, so you get a rating of 6.7 (the game rounds to 1 decimal). Now let's say you only made 10 of those builders into mages. Then you'd have 10 * 5 = 50 XP from the builders, and 500 XP from the mages, or 550 XP spread out across 60 people, or a rating of 9.2 for all the mages, old and new. And then every turn everyone's rating goes up by 0.5. Does that all make any sense? And does it sound any simpler than what you proposed?