I assume it varies widely. A professor with an applicable background makes or breaks an entrepreneurship class. I am not sure a poli-sci class would be that similar to business law, but I guess there could be some overlap? I have never taken poli-sci, but business law was really an introduction to contracts and business transactions that was great fundamental knowledge for business acquisition.
As far as you mentioning employee management classes being helpful, one of the classes I mentioned was employee management, specific to the service industries...'service management'. Honestly, after taking about every business class 2 different schools offered (transferred during my first degree) and then working for several years, only the very specific classes seemed to be worth anything.
A higher level marketing course I could see being helpful, but what I took just was not specific to any industry so I walked away with theories that I most likely would never put into practice.
As for accounting, you are not the first person to say how helpful that was, but I just have the viewpoint that the class was too detail oriented to retain for years down the road and to understand the basic terminology I would need to converse with an accountant would have taken a day of reading google or better yet, dentaltown.
All of this to say, yeah, you are probably right, it does vary a lot from school to school. The OP would be best off finding out who the good business professors are and taking classes from them. Business classes are very different from science, in that the background of a business professor can either add tremendously to a class, or take away from the value of it. The second school I went to demanded professors (from all subjects, not just business) worked for at least 10 years in the field they were teaching and this was fantastic for the student.