Check out the thread "Music overlap Again!" As i recall it got pretty heated in there about just this very topic. Good arguments for both sides.
Facts are - LMI don't get it cheaper to re-use the music, they simply choreograph for whats popular at the time, baring in mind that not all clubs run with all programs so wouldnt even be aware of the overlap. Also on the confusion factor, it was pretty much decided that it shouldnt be too confusing as all the programs are so vastly different in their moves!
Enjoy! 