There is just so much more to this than can easily be explained in a forum post but here is my boiled down view of it.
Firstly, and irrefutably the front wheel on a bicycle has the best potential for stopping forward motion on a bike, provided there is traction under the wheel. It is also the wheel that steers and as such needs to keep traction.
Secondly, there is way more to stopping your bike under varying conditions than applying simple hand pressure to a lever.
Whichever side you chose to put your front brake lever on it should not be used as the only brake and never as a switch. (Full on, or off). Appropriate modulation is what is required.
In a carving turn on loose ground or wet cobbles even the slightest bit more front break over rear can cause a no recovery washout and you will go down.
On a steep loose down hill any breaking to the front can cause loss of steering control and failure to weight the back wheel will promote skidding and again loss of directional control.
In an emergency stop on pavement, a non modulated strong application of the front brake without a significant weight transfer to the rear can send you right over the front wheel.
These are only a few of hundreds of breaking scenarios that you will deal with as you progress. Breaking is done with both hands and a shifting of body weight.
If your hands are so week or your breaks are so poor that your handedness plays a part in the setup of your bike then you are addressing the wrong things. The truth of the matter is that today there are brakes, pads and levers available for every possible application and user.
I have the traditional left front setup on all my bikes because it is traditional, but also because I feel it is the best setup for me. I have in the past, and occasionally still ride both two and four cycle motors, but that hasn’t changed my mind about having my dominant right hand power the steering and fairly simple one finger rear brake modulation while my left hand controls the more complex front brake modulation and timing for shifting rings.