yeah I agree although you don't have to do the CA pre req subjects technically, in practice Big 4 require you to have done CA subjects before employing you in accounting lines.
I think that CA rule is designed more for people changing careers (eg engineers, lawyers, non accounting finance people to accounting), so they don't have to do a Masters applied commerce or similar conversion course if they for some reason have some accounting knowledge. Most likely they'll still have to do a Grad Diploma in accounting in addition to the CA as its difficult to envisage where people are going to pick up the technical standards exposure, some of the costing techniques, audit methodologies etc. without having done accounting at uni before, hence it is unlikely they will pass the CA entrance diagnostic exam. This way it helps people like say ex-lawyers so they don't have to repeat Corporate law, tax law, management units so as to meet CA pre-reqs.