This is the entire point of my post. On a technical level to ensure how a system should work and interact with the the elements within only one needs to be working as a template for other systems. The other systems and landing zones are only a term of asset creation.
Like I stated in my post before, there are more assets closer to completion than has been released. Generic landing bases can be made off of templates of existing design. This is why I am pointing out the assumptions that each systems will take months to complete (as if they have to reinvent the wheel) makes no sense.
If the mechanics are nailed down after the first system is complete and unique assets created for landing zones, what exactly is taking the RSI team years to release? Why would you think so? I am not talking in abstracts, when we talk about milestones, the milestones are for the template to get one system up and running. What is sounding abstract is the time you are giving for each other system.
If we look at the concept art, as well as all the assets that have been released, announced, and leaked, there will be a very substantial number of original assets for virtually every system and planet.
The technical foundation for star systems developed via Stanton can certainly be reused, but not entirely. That technology will need to be expanded for the requirements that other star systems will introduce. For example, it may become evident that players need a way to climb or use a jetpack to get around (think about the Freelancer trouble during the demo). Hundreds of things like this, big and small, can and will happen. Certainly swimming mechanics will be necessary, as well as oceanic environments for that matter.
Finally, this still does not apply to art direction and design. Consider how long a single ship takes from concept introduction to in-game release, even with CIG's mature, established technology and art workflows. It isn't at all unreasonable to expect at least that amount of time for a star system. And just like ships, the complexity
increases over time, not decreases, even as new foundations are laid. Therefore, development doesn't necessarily get faster and faster (if that were true, a new ship would be releasing every week at this point). Ideally, it goes at the roughly the same pace, but more interesting things can be accomplished.