Right, if you want a SeaOfGreen, you could conceivably have 12 plants in there. Or, if you wanted to have 2 plants in Rubbermaid totes that are vegged for 2-3 months then that's an option too.
I like to mainline out to 8 or 16 tops and then flip. Doing it like that you could have 4 to 6 plants...