You have two 8 voice synths in a REV2 16 voice... one synth is permanently and physically routed to the A outputs, and the other synth to the B outputs.
If you play in split mode and stacked mode, the two synths are each on their own, working as 8 voice synths, either playing side by side, or on top of each other...
but if you play in 16 voice mode, the two synths are working together to give you 16 voices... they are daisy chained internally, but you have to understand that the two synths are STILL routed to their own pair of outputs...
The problem is that you think too much in layers... you think that layer A should allways play on the A outputs, but this is NOT the case when you play a 16 voice combined program... internally Layer A's program will be copied to Layer B, so that both synths play the same program, giving you the illusion of having a 16 voice synth... you do not... you have TWO synths playing the same program, each with 8 voices routed to their own respective outputs.
The only way to fix this 16 voice mode to come out of only one output is by either mixing the two stereo tracks in your DAW or soundcard, or to remove the plugs from the B outputs so that the REV2 mixes anything going to the B outputs into the A outputs.
There is absolutely nothing wrong with your REV2

... only thing you need to do to make things the way you want them is to take out the B output plugs when you want a 16 voice program to enter your soundcard on only one stereo input... I know this is not what you expected, but unless you have the means to mix stereo channels on your soundcard into one stereo input pair, then you need to pull the plugs on the B output to get what you want when playing a 16 voice program.
This way of physically routing the A/B layers is the same on any DSI synth with an A/B dual capability... Prophet 8, Prophet 12, REV2 and Prophet X... they all do it this way
