In addition to the number of course hours that are prescribed, note that schools differ in their willingness to let students waive core courses in favor of more advanced courses.
For example, HBS is fully prescriptive in the sense that it does not permit any waivers.
HBS
"Because our aim is broad, foundational, interactive learning, all MBA students undertake the same course of study during the first year of the program. Individual courses in the first year cannot be waived."
In contrast, Chicago is is very willing to allow students to take more advanced coursework in place of the core class if they have already mastered the subject at the level of the core course.
Chicago GSB
"our extremely flexible curriculum offers options for fulfilling even the three required foundation core courses. You will not find yourself forced to repeat courses you have already mastered."
For some candidates, the fact that all students must take a large number of the same courses is an attractive prospect. A large number of core courses allows extended interaction with classmates and less "fragmentation" relative to a curriculum that is largely self-directed. On the other hand, some candidates find "lockstep" programs needlessly paternalistic and force students to take coursework that effectively duplicates what they have taken previously.
It seems logical that schools in the leader/manager mold would favor lockstep/no waiver curricula. After all, if business school is designed to teach students the craft of management, the idea of exceptions or substitutions in this process borders on anathema. On the other hand, for schools in the "analytical toolbox" mold the idea of waivers makes perfect sense. If a student already has (say) a degree in economics, why not let that student develop more advanced tools by taking a higher-level course in economics.