With so little said about the details of how they're going to fulfill the mission requirements, it seems like the scene in a Dirty Harry movie, thusly:
One could legitimately ask if SpaceX really knows what they're doing here. Of course SpaceX knows rockets, but they've never done this kind of thing before, which is something that they've got to master before they can be successful.
Why not copy what worked before? What worked before was basically the solution for the tyranny of the rocket equation. NASA's solution was shed mass as you go along. The Saturn V's first two stages did the heavy work of getting to the edge of space, then the IVB third stage finished off the orbit phase, and served as the translunar injection phase. After its job was complete, the mass was discarded, as were the first two stages of the Saturn V. At this point, there is about 100k lbs that has to finish the mission. That's just 50 tons.
No need for complex operations like refueling in space. The last part required only a relatively small amount of thrust and fuel. Even that obeyed the same strategy. The lunar module had two sub-modules. The lander part got the lunar module on the surface, and the ascent module got the astronauts back to the command module. Let's say the lunar module massed out at 16 tons. That left 34 tons to get back to Earth. To get from the lunar surface required only 10k lbs or 5 tons total mass. These are approximate numbers, but that's not the point. The point is that in landing such a large spacecraft on the lunar surface requires a very complex set of maneuvers.
Refueling may work, but the shedding of mass has been proven to work. So SpaceX is basically re-inventing the wheel here. With the heavy lift capability of the superheavy, it should be well within its capabilities of landing a spacecraft on the moon. Just not the Starship. If Musk insists on the Starship, then he is incurring far more mission risk on something that hasn't been proven in action before. Just sayin'.
