You should be aware of the following disadvantages and risks if the subjects correspond to different schools at your host university:

Your joint honours degree programme requires you to take courses for both subjects in the 3rd year abroad and in your 4th year in Edinburgh, which will restrict your options. Some universities will restrict you from accessing courses of both schools. Even in the case of single honours, many of our study abroad students experienced that the courses they originally planned to take turned out to be full and unavailable after they arrived at the host universities, and they were forced to take other courses, some of which did not match well with their degrees. This seems to be a bit more serious for joint degree students.

SWAY organises several events on international exchange programmes. You might find more information there.