Before my DS was placed for 1st grade, his K teacher suggested that I talk to the principal to place my son with a teacher who's strong in both academic and social skills and a few kids who are close to my son's academic level to help him socially. They did exactly that and I am very happy with the result, especially socially and that was our main concern when he entered 1st grade.
I don't think it's too much to ask, IMO. You want your son to have a peer who he can relate to better. They help either other socially and academically. Having all five of them in one class may not be possible, but just two or three of them together would be beneficial.
