Board Thread:General Discussion/@comment-24184449-20150411221338/@comment-4287993-20150412060748

I kind of feel like the number of main characters is tied to the characters' position in the hospital. In the first seasons, the main characters were interns and didn't really know anyone but their close colleagues, as they were working too much to have a lot of free time. Then, they became more skilled and got to work with more attendings on different specialties on more difficult surgeries. Now they're attendings themselves, often finding themselves working together with other attendings from all the different specialties, all the while training future surgeons themselves now. So, the number of characters just is representation of their position in the big hospital. Big hospital, more colleagues.