Equally varied the opinions of people about whether or not having student with different abilities study together is more beneficial.
As essaytest comments, here there is a slight confusion about whether you are answering what your prompt suggests. The argument is about, in simple terms, whether the schools should select students solely upon their academic capabilities or not. In other words, whether students with different abilities such as talents in sports, music, drama etc. should be considered for selections or not. So, you need to introduce these two sides to the reader in your introduction. I believe you have grasped the idea and tried to express it in the above sentence. However, it has not come right and that's why you had that comment from the essaytest. I suggest you to employ more direct speech and simple, yet interesting sentences. They are more powerful in conveying your message to the reader.