Even if it could be proven that one course is harder than another, it doesn't follow that an employer should value one over the other. It might even be preferable to chose the simpler course over the harder. The field that I study, in the Biological Sciences; having a good grasp of general concepts, and having practice in the lab, is of more value than extra concepts. It can be easy to make a course harder by increasing the number of concepts a student has to learn - but that can detract from what is actually important to the employer.