qi-tah
Brown Belt
I think there's a difference in a SCHOOL that intentionally and consciously cross-trains various styles and a student who tries to balance TKD Monday with BBT Tuesday and Choy Li Fut Thursday. When the school (hopefully, with instructors with proper training in each art, not weekend certificates!) puts the syllabus or program together -- they're doing it with a plan or structure for it. A student running independently does their own thing, there's no guarantee that what they put together will actually fit coherently.
Yes, i totally agree, but what i think you get from a school/class that has more than one art in it's syllabus is more than the practical - it's a sense of possibility, of openess and curiosity about different ways/systems of moving and fighting. At least that's been my experience. And that approach might actually prevent you from cross-training outside the school for a while ('cause you have enough on yr plate at the one school), giving you the time to improve to the point where a bit of experimentation will work with you rather than against you. Possibly...?