My four other courses aren't combined with other sections. My small section doesn't have LRW and one other course exclusively. So I wouldn't say that every school "more or less" does it that way.
The only difference between the Harvard system and my school's is the unit defined as a "section."
Be more specific.
I have 4 four courses with the same 80 students. LRW is split so that 40 of us have it one day and the other 40 have it another. This semester I only have classes with those 80 students, my section.
Next semester I have 2 courses comprised solely of the 80 students in my section. LRW is split the same way again. We can choose one elective which can be with anyone, 1Ls through 3Ls. Our fourth class is one in either international or comparative law. I think there's 6 options. That class is only 1Ls, but it is not limited to my section.
Harvard would be identical to the other schools if "the other three courses you have with 2 other sections" are with the exact same sections for each class. The earlier posts make no mention of whether the three other courses are always with the same two sections. If that's true, then the difference between the two systems is nonexistent. The other schools have smaller LRW sections. That's it. If you aren't having classes with the same 80 students for over 3/4 of your 1L year, then I wouldn't consider Harvard's system to be exactly like every other school.