It was something to do with code I commented out in the past. I cleared all those lines out then ran the code and it worked! Not sure where the snag was exactly, but the nested arrays was the way to go. Thank you for your time and energy @pyrrho & @ScottR , this was a huge huge huge help!
The JS query function above works fine as well... to @pyrrho 's point
I think the lodash
_.mixin is what you are looking for. It will create an array of the unique items from both arrays.