Well, my babies were 8 lbs. 12 ounces, 9 lbs. 4 ounces, and mostly recently, 8 lbs. 11 ounces. All were around 21-22 inches in length. And, the NB dipes didn't fit.
With DD1: The OC prefolds didn't fit into the NB and S size wraps.
With DD2: The Kissaluv size 0s were too small on the rise.
The NB size diapers: no way.
With DS: Many of the smalls don't fit. The serged-style FMBG AIOs don't fit in size small, but the fitteds and AIOs with FOE do fit....