A majority of mids will pick Group 1 or 2 anyway, the STEM quota never comes into play.
Aero was extremely competitive for '16. I remember hearing that they did screen plebes for that one. Good grades in Calculus and Chemistry were key.
Cyber Ops as well, but mostly because it was a new major with very little faculty support at that time. They could only have forty mids in the major.
Some mids will be encouraged to switch majors or placed on probation for Group 1 in general if they received poor grades in Calculus and Chemistry plebe year.