I prefer Bynum leaning on Baby instead of on KG and Sheed. Sheed has been swinging a lot at opponents leading to very high fouls per minute. Baby is also in better physical conditioning. With Sheed's back, I don't want Bynum leaning on him much.
I also prefer to be in a position to always have either Sheed or KG on the floor. If we are stuck bringing in Williams at any point, I would rather see him on the floor with Sheed than with Baby.