If you think about the world economy today, RGOs in remote regions (oil rigs, wells, mines) actually have very few workers. They're mostly mechanised. Meanwhile, the amount of GDP created in cities like New York, Tokyo, or Hong Kong far outweighs that of less populated, more resource-intensive regions.
In space, you're likely to see "tall" planets (Coruscant), and those where machines do most of the work (Mustafar). What I'm basically saying is that the output of a ship production factory would be mostly affected by how well the engineers, technicians, and end-users can communicate and understand each other's needs, along with how standardised they can make each design (remember that diverse empires need to make adjustable cockpits which fit mushrooms, galactic goop, and giant reptiles, and systems in multiple languages).
In the areas where production matters, you get better results. Plus, it would work well within the context of the game, having a trade-off between research, and production. Obviously there would be other factors influencing both, but it's a reasonable trade-off.