Well if Reid's alibi is that strong he can get out from under this garbage as soon as possible. The other defendants might like him to go forward and get acquitted or have the case dropped on him so it will kill the raped by 3 man theory.
FWIW, I think they're all their own best defense when combined. Two already appear to have terrific alibis, and if rumors are true, there's even more exculpatory evidence going to show up. I'll bet the defenses have no intention of severing.