I would recommend leaving everything from factory as is.

If you need more lights for reversing then mount additional lights.

On cars I know reverse lights are not included into the computerized bulb check circuitry, so I would consider replacing them with LEDs a fairly safe undertaking in terms of not getting computer errors afterwards.

LEDs (when used as a direct replacement for ordinary bulbs) often cause a different sort of problems : if you just install them not adding additional LED driver units, they in most cases will start flickering rather sooner than later, and will die afterwards. Even expensive LEDs are prone to that, so it is always a gamble: will they hold over time, or not. The reason is  that even 12V is a little too much of a voltage for normal LED chips, while in cars voltage often goes as high as 14V, which for LEDs is murder, unless very specific voltage and current limiting measures have been integrated into the LED circuitry by the LED bulb manufacturer. These manufacturers often save money on sophisticated measures needed to accomplish this task correctly, and just add some cheap resistors instead, which too often prove to be not enough for guaranteeing LEDs longevity. The only two manufacturers I can name based on my own experience who are manufacturing LED products which are guaranteed to hold up over time are Philips and Osram. 

In addition to the above problem, especially in applications where you want to be getting a light beam of a specific shape (like with backup lights), much depends on how well your specific led bulb shape matches the geometry of the reflector. Light emitted by an ordinary bulb  is omnidirectional and relatively easy to shape to the desired beam form, while the directional light emitted by a LED bulb is not. So often you will not be happy with the result of such an upgrade just for the reason of the specific LED bulb not really being able to properly unfold its potential when used with the existing reflector.

I would therefore recommend that you look into a different solution: into buying a pair of ready-made aftermarket LED rear light assemblies, where the LEDs are put in the framework required for them to do their job  best.