It depends on a few variables. When I wrote it as the fifth assignment, I assumed the student had tackled the first four and was comfortable with researching and writing their own paper. I also wrote this book with the idea it is for a 10th or 11th grader. If it is a student who is used to this assignment and wants some academic freedom, I would allow them to structure the essay as they see fit. If the student requires more structure, I would suggest they follow the following advice:
Since I prefer chronology, I would instruct the student to first show what the evidence states about British imperialism from the beginning to Indian independence. Then, at the end of the essay, in the last body paragraph or the last two body paragraphs, I would have the student write the different views of British colonialism. Take a look at the prewriting activities included with this assignment. The first is about the history of British in India. The second is an Englishman's viewpoint of colonization, and the third is an Indian's viewpoint. The student could follow these activities as their rough blueprint of how the essay could be structured.
I hope I have answered your question. Please let me know if the answer helped.