In fact this is 90% of what being a good surgical resident is all about.it's interesting how there's an accepted way to evaluate undergraduate work, i.e. by science GPA, for med school but for med school to residency it's become contentious all around, including preclinical grades
perhaps part of it is that 90%+ of a US medical school class is smart and hard-working - you don't have many people who don't take tests well but repeatedly get drunk the weekend before an exam. a lot of the variation in preclinical grades can be attributed to weddings, background, family issues/commitments, illness, being traditional/young with few distractions etc. rather than from memorizing ability alone
basically the only way to discriminate between students in an objective way in the preclinical years is by seeing not just who has the most sponge-like long-term memory but also the greatest fortitude, and freedom from commitment, to grind for hours on end. doesn't seem like the best way to choose future subspecialist surgeons
it's a tough situation all around though, so it's difficult to see a solution.