That's like asking us to choose between Jack and Coke...one is not very good without the other...
I like both of those together and both of those separate. What does that say about me?
It says that comparing light which can't be combined, with drinks that can doesn't make for a good analogy.
Light can't be combined??? What do you mean? Sure it can. Add fill light. Use subtractive fill, aka "black cards"...use multiple sources of light, with bright sunny light as main light, and reflected light as fill...use sunlight as main light, and flash as highlighting,rim lighting, or side-lighting...on overcast days, use cloudy light as main light and use fill or flash as accent lighting.... you know, use a "mixed" light source approach. Get it? MIXED light?
Light can't be combined...quite a facile statement. If there is too much sun, move to a location where you can find shade, or open shade; BOTH offer absolutely dead-easy lighting for all types of photography. Whenever there is bright sun, "shade" can be found, or created, pretty easily.
Feel free to use sunny light as front-, back-, or side-lighting, and the same with overcast light: use it as front-, or side-lighting, or even, back-lighting! zOMGosh!!!
One of the absolute BEST types of light is a combination of overcast skies with bright sun peeking through clouds...it's a "mixed lighting" scenario, often referred to as cloudy-bright. Another type of combination lighting is one I personally LOVE: the days (or hours) when there are dark, stormy, or rainy clouds, with large expanses of sun light streaming through the clouds; some of the most lovely landscapes are made under that kind of lighting. Oh wait--we cannot "mix lighting"--ballistic said so!!! We must have only one kind of lighting...we can not combine lighting types!!!