Indeed, Pontiac is easier.
To answer the question, our legal system goes back hundreds of years. It has been well developed and is very pragmatic. There is a reason why we have trial judges who are familiar with cases. They know what went on; they hear testimony. It is up to them to come up with a sentence to fit the crime committed.
That is why appeal courts do not hear testimony. They make rulings on specific legal questions. In our system, the trial judge is the one familiar with the case. Neither the appeal court nor the Supreme Court, and certainly not the House of Commons, is familiar with every case.
Members of Parliament must not think that they know everything about everything. It would be quite a bill if it took every possible situation into account. If people truly wanted to work on such a bill, it would be a lifelong project and it would never be done. We must not think that we are that smart in the House. We do not know all the facts. The trial judge is the one who knows the facts, and it is up to him to impose an appropriate punishment.