I've also seen planes with multiple RX's just in there to make life easier. like a multi-engined plane that had a full flight pack in the wings. The result was no wireing to be plugged or unplugged when removing the wings. Just remember to charge both RX packs! (wing RX controlled throttles, flaps, wing mounted retracts, and ailerons. fuse RX controled nosewheel retract, rudder, elevator, and some other stuff)

Lots of differnet reasons to do such a thing.