If you can apply some theories to the basis to the Mars projcet failures. We may have a more base reason than failure of quality controls these projects.
Hypothesis based on location of various landers, the prior posts this thread and success or failure rate. It appears that as the projects locations of MARS projects gets closer to the North and South poles. The failure rate increases. Reason they are failing because of adverse magnetic affects. Nasa has failed to take into consideration the degree of variables Mars versus Earth Pole Magnetics.