The NPAS model is 1 + 8, certainly is in the only existing NPAS region (SE). The rational of the regional model is to fill the gaps when individual bases are off line for whatever reason. The NPAS cloth has been cut to suit a budget and the management freely admit that 1 + 8 won't cover all situations, but would argue that the next base along will cover. It's not ideal, but it's all about the money.