How many deliveries do you see? Are you not ever able to get anyone from OB down to the ED if you have someone coming in for a delivery who can't make it up to OB? With as expensive as it is to offer NRP and maintain certification for the staff, and considering the number of deliveries the average ED sees (in our ED, which is a large level one trauma center, they call OB staff who come down and manage the deliveries, so there are usually NRP certified staff in attendance at most ED deliveries), I would say it's probably not cost effective or beneficial. NRP is a use-it-or-lose-it skill. Even in our OB, without regular drills and mock codes, many staff forget how to do it, and they still have the opportunity to do it for reals on probably a monthly basis.
The vast majority of the NRP rubric is designed for delivery and the immediate postpartum period. Once they're outside that, then your PALS skills will usually suffice.