&quot;what the rest of the system does has no real part to play in the landing of the rocket stage&quot;<p>That assertion is ridiculous. The rocket is optimized to do one thing, push it&#x27;s payload into orbit, this is a very strict restriction, especially on a two stage rocket. On the other hand, the designer of a suborbital vehicle has ample design space to play.<p>It&#x27;s like comparing your practice free throw, in your back yard, with a slam-dunk in the NBA.