Number of plants doesn't do much to indicate yield. You can have one mongo 12-foot Sativa plant that gives you 1000 grams, or lotsa little plants that give an ounce per plant. There are a great many variables, but lighting is the primary limiting factor. But strain, how long you veg them before flowering, nutrients, pot size, ventilation, temperature, it all has some effect on yield.

In fact, depending on where you live, you might want to grow fewer large plants rather than numerous small plants, simply because of the laws.