I think the point is that a staged rocket is clearly "better" in theory, but adds a step-change in complexity and overhead that might not actually be required.

I think the point is that a staged rocket is clearly "better" in theory, but adds a step-change in complexity and overhead that might not actually be required. It adds a non-zero chance that the mission fails catastrophically due to a defect in the staging system at a critical moment, or the design process overtakes the budget and the whole thing is scrapped. In either case an N-1 stage rocket may have done the job. Doubly so if you are experts already in single-stage rocketry, but lack staged rocket design and execution competence. Akin's Laws¹ of Spacecraft Design have a few relevant ones: > 13. Design is based on requirements. There's no justification for designing something one bit "better" than the requirements dictate. This is not the only one that's relevant. Also 15, 27, 33, 34, 36, 36, 38, 44, and, if you substitute "distributed architecture" for "launch vehicle": > 39. Any exploration program which "just happens" to include a new launch vehicle is, de facto, a launch vehicle program. Of course, if a staged design is actually required (and not just because your engineers need to buff their CVs so they can jump out when the project fails under its own weight): > 41. There's never enough time to do it right, but somehow, there's always enough time to do it over. ¹: https://spacecraft.ssl.umd.edu/akins_laws.html https://spacecraft.ssl.umd.edu/akins_laws.html