You seem to have your mind set so I'm not going to argue with you. I just don't think it's anything to worry about - the little advantage you may have will be gone after your first week so if you like Legal Studies, great, if you're doing it to help out in Law School, you're going to be disappointed.
Legal studies was a waste of time from the p.o.v of my law degree. Didn't help me in the least. Helped my UAI though. It's a ridiculously easy subject, only worth doing for people who can blitz it.
I'm sitting my HSC this year. I have a few family members who do law as a profession and they said that you don't need legal studies to do law at university and you are at no advantage what so ever but it's nice to have a prerequisite knowledge (not that it would benefit much later down the track)
Anyway, I believe that doing the subjects you love in high school is the most important thing (I love legal studies so much