re: Building Straw People?
First, an assembly can be made at higher altitudes and over weeks and fueling can happen at the end of this assembly.
Second, there are other ways to store fuels...like as water.
Third, you haven't being pay any attention to this M, M and B thing because the Moon is going to be a filling station for Mars and beyond.
Fourth, there is always a second test of a system to fix problems if it takes DART to do it.
Fifth, HLV.
Sixth, Mars in this "plan" is at least 25 years away...