How does area and intensity relate to perceptive brigthness of a light source?
One of the best ways to evaluate the various configurations that you have raised in your question is to actually build them up as prototypes and then take a look at the results.

This method also allows you to get multiple evaluators into the game and you can test in as many sets of external sets of parameter variations as you can make time for.

The experimental method is a powerful engineering tool and often leads to discoveries that you never anticipated when you first started out.