You need to read the UBC and not just the NEC.
In fire rated walls boxes must be mounted to the studs, (no "cut-in" boxes unless maybe you can cut them in next to and mount them to the stud instead of useing "hold-it" clips) Boxes in opposite wall faces must be at least 24" apart center to center. (to insure that they aren't in the same stud space.)
The UBC also specifies the sealing methods around penetrations in fire walls. You won't find an article in the NEC to qoute or to dispute with the inspectors. If you want to be informed you will also have to be familiar with the UBC codes.
No I'm not trying to be a smart aleck....just stateing a fact. It takes more than NEC knowledge to perform and comply as a proffessional nowadays.
