So i've just harvested my first grow from under 555w of cfl bulbage and to be fair, it wasn't a bad haul. A little bit fluffy but that was due to heat issues i had in the last month. The only problem is that i had a lot of smaller buds rather than the large main colas you normally see, mainly due to the fact i had little lighting in these particular areas as the girls got quite bushy and wide and hid a lot. I had 3 plants this time but i was thinking.... if i have 2 plants under the same wattage of lights, would i reap a better harvest than the 3 based on things like more lumens per plant from the light available and more light being able to hit the plants from all angles??
when lighting is limited, less is always more! But you can work with less coverage by rotating your plants 1/4 turn a day. But in your case, yes, it is better yield wise to grow fewer plants if you don't have the supply of light to cover them all. Believe me when I tell you, (1) plant can yield more than (4) plants if you truly only have enough lighting to cover one!