I had coffee today with a professor at INSEAD. We talked about whether the way the courses are laid out at the school makes sense from a student perspective. That is the order in which the core courses are proposed. It certainly makes sense from a logical progression on the ladder of knowledge.
The question that we debated was whether it was good for the student from a psychological perspective. Now, this is one of these discussions in which people can do and redo the world, lacking all the data that they would need to really make up your mind.

The debate centered around P1. The P1 courses are more math-oriented on average than P2's or P3's classes. The participants with no math background must find P1 very difficult. Bankers and engineers must find P1 very easy. Apart from OB, all of the courses are fairly number loaded.
The great majority of group work is finance-related. Bankers have it easy but others might struggle. It is plausible to assme that the people struggling in finance might be the same people in need to dedicate more time to the other courses.

Actually, I very well remember some "poets" as INSEAD nicknames them tell me that P1 was definitely hard on them.

The first period is key to anyone's impression of the course. Although one could argue that the whole MBA program is a very intense year and that everyone should expect to work like crazy, it is possible to make an argument for a swap between core courses in P1 and P2. Perhaps bring some Marketing or something similar.

INSEAD does provide math courses before the start of the course for anyone who wishes to brush up their skills. There were also numerous tutorials available. They do take time but they certainly ensure that participants can pass the exams.