I was packing about 8 girls under a single 1k before last week, so it wasn't great. However, I will admit to favoring these girls, so by no means were they shaded in the corner of the room, they were in the most ideal space under the light.
I'd have to say over pruning must have been the cause. I have only allowed 4-6 main branches, removing all other shoots. This was kind of an experiment, it worked fine on other strains, and allowed for more girls under a light with less popcorn and more quality buds. These girls were obviously overdone, lesson learned.