Novel writers like Jules Verne or Arthur C. Clarke get as far as the level of detail of my Excel spreadsheets and call it a day. They can control how the characters move, what the plot complications are, and if something calls for a new area of the ship to be invented, he or she just has to provide enough detail to convince a teenager reading the book by flashlight.
Ships for TV and film are usually designed in a similar way. Figure out what is going to be on camera. Provide enough detail for the viewer to suspend disbelief. Only this time they have to actually fabricate those scenes. Somebody might run the math, but usually the details they have to get right are visual. Some feature is added for a fight scene, or a dramatic death of a character. It doesn't have be actually be all that internally consistent. (Although the better productions are consistent.)
Given the interactive nature of the Iliad, I don't have the luxury of controlling the camera. Players need to be able to get out into the ship and do things. And even get themselves totally lost. And when they wander off where the story line is supposed to lead them, there has to still be something for them to see. If they read a sign, that sign needs to be part of a system to guide them back to the parts of the ship they are "supposed" to be on. That consistency requires a hell of a lot of design work. In some ways even more than if I was having a team of graphic artists lay down a digital set.
Do I have to be this detailed? No. But did Tolkien have to invent a bunch of languages? Also no. It's just something that artists are driven to do.
My game doesn't have graphics. So instead it will have to exude details and internal consistency. If you hear a sound of banging on the roof of SA05-01-345, you know the sound is coming from the floor between SA10-01-340 and SA10-01-000. If a design element doesn't make sense, on some terminal, somewhere in the game, is a document explaining why. In fact, I need a lot of strange things. Places where an otherwise orderly system has to break for some mission detail. Those jarring little consistent-inconsistencies define what it like to be on board a ship. Even a cruise ship has odd bits of naval architecture that they just cover in sheet metal and hang a chandelier off of. But it is still there.
Jarring details include:
Anywho, back to number crunching.