Is that not the case now for military ships? Assuming of course you aren't making something really small like a fighter.
Not in general, because there's a legitimate tradeoff between adding a module versus another component of relevant type.
Survey ships are one easy example, you can add a Science Officer for 3 HS or another sensor for 5 HS. Whether the officer station is worth it or "better" depends on how many sensors you already have (therefore ship size), how much bonus you expect to get based on your commander roster, and whether the tonnage might be better used for, say, a Main Engineering (maybe you value reduced breakdown/MSP consumption more than survey speed?). Of course, if you build your survey ship big enough then you can just put everything on it and call it a day, but I don't think most people do this.
Tactical Officer is another one where you have to consider if the tonnage allocated for the module is giving you a better net DPS output (or PD hit%, whatever the case is) than another weapon - even more so if you run mixed-used ships in which case the total tonnage of weapons mounted is not the same as effective firepower in any given scenario. Again, you can run your ships so large that it's a no-brainer every time, but that's a separate decision and doesn't take away from the fact that ships in the medium size range have some interesting decisions to be made.
Compare to a typical proposed commercial station: a Mining or Terraforming Officer is going to be a negligible amount of tonnage and cost compared to the massive size of a typical mining or terraforming station, so it's a no-brainer every time unless you make the station something completely ridiculous like 25,000 tons in size. That aside, I wouldn't
mind having that in the game to promote officer usage and a deeper logistics side of the hierarchy, but there's no interesting decision being made there so I can see why Steve has not been interested so far.
