I agree with gokings814 - I think the current system both ensures geographic diversity and gives SAs the ability to choose those with high WCS regardless of where the candidate lives. Technically there are something like 5,300 nominations from MOCs each year and only ~640 ((435 reps+ 100 senators+ 1 VP (ignoring territories) )* 1.2 appointments/yr/MOC) from MOCs each year per academy. That's roughly half the admitted class. The reps are distributed at approximately 1 per 725 thousand US citizens (316million/435 house reps) so populous states/areas should have more attendees than less populous states with the Senators ensuring a somewhat disproportionate weighting to low population states. Those going into the national pool (i.e., with a nom) should still be representative of the highest WCS candidates available in each district/state and can be selected for appointment without regard to geography. Other nominating sources (Presidential, ROTC, etc.) are not geographically limited which allows for additional flexibility on choosing high WCS candidates. This is somewhat borne out in the numbers if you look at a recent article that showed the distribution of MIDN at USNA by state - CA, TX, MD, VA, FL were top 5 at USNA vs population rank of CA, TX, NY, FL, IL (MD is 19th and VA is 12th by population).
Very long winded but gives some support to the current system, in my opinion.