Normally, we use one-three-five-odd# in a series, for photography and art composition. I happened to like the composition for the closeup posted earlier with a pair (two with one in bokeh behind them) this time only. Sometimes you can break the rules but you have to know them and know them well, first.
Still, when working with pears or apples or tomatoes in a grouping, for example, I would compose and shoot one pear alone and explore all possibilities with light and shadows, then three, then five. I may then go back and re-shoot five while cropping out edges of the series (grouping). Sometimes just following the rules and not experimenting leads to sameoh-sameoh images; bending or even breaking the rules may give you freedom to explore other possibilities. However, learn to drive the car (camera, lens and flash unit) before you experiment.