I think they should add a First Year Dormitory and leave sorting until the end of term or at the beginning of second year. I think beginning of second year would be better, but the first years should be more restricted from associating with the 3rd-7th years due to deeper rooted rivalries. Wouldn't want to expose them to this animosity between houses. This arrangement would prevent 1st years from participating in Quidditch, but balancing sports and schoolwork is more difficult at a young age, so all the better. The first years learn their strengths in magic, then get sorted into their respective houses. What do you think?