Mine is that: (xbox one controller) | (n64 controller) A button A button X button B button RT / LT Z button Start button Start button Left analog Analog stick Right analong C buttons Dpad Dapd RB R LB L
That's the layout that I think making the most sense, beacause if you play a N64 game you often use either the joystick or the Dpad to move, but never both, so even if you run two seperate games and one you the Dpad while the other use a joystick you won't get confused between the two controls because theyr'e pretty similar, and even if there are games that use both (and this is pretty rare), then you would be able to switch very quickly from the Dpad to the joystick.
The LT/RT buttons are most close to the Z button, and holding it down and pressing the buttons at the same time is more comfortable than using the R or even another button to accomplish the same thing.
Sorry if the grammer is not perfect.