I don't much like the idea to scale dynamically the modules, because it would make really hard to design ships so that everything "fits". Say I want to make a 12000 ton ship (so it has a fixed speed, equal to that of the other fleet elements) it would be hard to design it precisely.
I want to further expand on my idea of multiple, different sized modules which can be chosen for the various positions.
Don't think this is a good idea, why should a larger ship get a larger bonus out of the same officer? I would rather say it should require a bigger module to get the full bonus.
Consider this example, to explain my point of view. Also consider there IS a lot of automation in such a futuristic setting obviously.
Let us say we are talking about maintenance and repairs, so the module would be Main Engineering. There could be, say, 4 possibilities. All numbers are just placeholders.
- No module whatsoever. The ship doesn't have any special space and officer allocated. In case of problems, the commander does what he can at half efficiency like Steve said before, coordinating the various automated repair systems. This would be the default for most civilian ships, and maybe for grav surveys at the like. Fighters too.
- A basic Main Engineering small module, 100 tons and just the officer assigned to it. A small space where a dedicated officer can coordinate multiple systems, control the various parameters, organize the automated repairs and perhaps direct some repair robots. The default solution for most small military ships or valuable civilian ships.
- A medium Main Engineering module, 200 tons and 5 extra crew. A largish space where the officer and his aides continuously check up the state of the ship and coordinate repairs in case of problems, with better equipment at their disposal. The officer gets a +5% bonus to his skill because of that. Default solution for medium warships or important warships/civilian ships.
- A large, fully equipped Main Engineering module, 500 tons and 15 extra crew. The best possible accomodation, for large warships or very important and/or unusual ships. The officer gets a +10% bonus to his skill because of that.
I think a system like this would be enjoyable, and could lead to many varied and interesting designs. Plus, it would force you to make compromises on everything but the largest ships.