Supposedly, it is a very small group. 20 ish is what I remember as well. I think there are 4-5 3D modelers and then the programmers that turn it from art to working ships. They have more people working on other things too, like art for hangars, art for truck stops, art for cities, etc. programmers will be working to hook these up as well. I suspect that one of the reasons for the procedurally created areas is that they can create a few hundred critical variations on items, and then they hook up in lots of different ways.
For example, there may be 5-6 versions of dumpers depot. 4 different gun shops, 50 different stall types, 3 Casaba layouts, 4 different hospitals, 8 different EX habs, etc. then these can be put together in unique ways. This area is richer. Put in casaba, medium hospital with expensive beds option, a speed shop (fancy version of dumpers) 500 upper end apartments, high end hangars, high end ship seller (sells origin, RSI, etc. does not carry drake or military ships.). Fancy armors, high end personal protection goods, no refineries, etc. These can then be put together a couple hundred different ways for a huge number of city areas. Same can go for middle industrial, and lower class areas, as well as criminal areas. That means they need lots of artists, and people associated with making those models work to generate the templates needed so that you don’t just have the same high end city, industrial complex, pirate base, etc with different layouts.