This was popular a few years back, but I believe most are now going back to a single RX. The theory was that by using two rx's, you could still land the plane if one of them failed. You wire on RX to drive one aileron and one half of the elevator. the other RX drives the other half. put the throttle on either one. If one RX fails, you can probably land the plane (maybe). These big planes usually have two independent elevator halves, each one driven by its own servo. They are mechanically independent.

Receivers are so reliable these days that I think the extra RX does not really add anything. Most of us DO run dual batteries into a single RX. the batteries and switches are more likely to fail than the RX.