You would do a general Law degree, not one in 'Corporate Law' - thats a specialism at postgraduate level.
So, taking Business Studies not going to give your friend/ any advantage at all.
There are no required subjects for Law - so entry requirements will be stated as just 3 grades.
Most people find taking at least one essay-based subject useful for skills / LNAT but this is not essential, and its totally possible to do a Law degree with three science A levels. You certainly dont need to take Eng Lit, and many people find Politics, Sociology, Psychology etc a better fit.