USNA does not publish its WCS algorithm, but I heard at BGO training in the past that the Math score is weighted heavier than the English score, perhaps as much as 2X. The average of Math/English is really irrelevant ...they are two independent scores that are intended to measure your academic aptitude in two different disciplines.
As others noted, USNA is STEM oriented, even for a Group 3 (Bull) majors. To be "qualified" for Admission, you need to demonstrate the aptitude to handle a rigorous STEM curriculum, including good SAT/ACT scores, and record of performance in advanced math/science course in high school. You should also keep in mind there is a difference between being "qualified" and "competitive" --even if your record is sufficient for Admissions to consider you qualified, you will not get the appointment if another candidate in your slate has a better record. To maximize your chances of admission, you need to get that Math score up !