The common QWERTY keyboard is designed to break up common letter pairs for typewriters, so as the mechanismss wouldn't interfere with each other. This carried on with computer keyboard. The AZERTY keyboard is designed for use in France and Belgium, where the language did not use the same common letter pairs as English. There are a few changes, and yes, shift is needed for the numbers (though I have heard you can swap these somehow).
The keyboard you're thinking of, Tolwyn, is the Dvorak simplified keyboard layout... which is superior for any job that requires non-stop typing, as the letter combinations are much more natural to the English language. This type of layout would never work on a typewriter, but those limitations don't exist on computers. It technically IS superior, with training, for use with the English language.
In short - QWERTY okay, AZERTY for French/Belgian, Dvorak best for English (but not very popular)