JD/MBA Applicants

It might be allowed for the JD/MBA only. I think the concern with the other schools is that if you get into a school that is much less selective, say the Divinity School (don't yell at me if Divinity school is very selective, i don't have #'s to back this up, it's just a theory) and then you apply to a school that is much more selective, you already look better because you're in another Harvard school. So the other school feels pressure to accept other Harvard students because you don't want to reject your own. But, many people were doing this, and it negatively affected the number of seats they had for new admissions. If one Master's degree from Harvard is good, having 2 degrees is better.

As for 3 weeks prep on the LSAT. Good luck to you, but I hope your expectations are realistic. The are a few people that can sit for the LSAT cold turkey and score great, but those are very, very few people. As an LSAT and GMAT instructor, each test is difficult. People that take each test and not the other may think the other is harder. LSAT takers because they're not math inclined, and GMAT takers, because the Math doesn't scare them and they put up with Verbal because they have to. LSAT takers are just arrogant by nature because they're going to be lawyers so some of them may say their test is harder simply because they want to say that