Sociology is difficult in terms of juggling theorists, concepts, sociologists, and time periods in which specific events happened [e.g., suffragette periods], but it depends on what it is you're filing under "rigorous", it's quite subjective imo. Sociology might be easier for someone who's naturally good at English and has very good argumentative skills in writing but not so good for someone who is more into mathematical and factually proven things as sociology has a lot of philosophy and "what if" topics involved. At the end of the day, do your research and see if you think the topics would be difficult for you or not