results per plant?

I am just curious: If you have 25 plants under 2000 watts I assume you can get a harvest of around 3 lbs. Now if you only put 10 plants in the same area of the same type of plant are you still going to get the same amount of bud? What about 5 plants? And would it be in the same time period or would you have to veg longer with fewer plants to get the same results?
Also is the 3 lbs. dry or wet weight?

Is there anyone with any insight into this? I am also curious if you are growing different types of plants short and long flowering types in the same are, Will the yeild increase because after the first bunch of Indie is harvested the light is focused only on the sativa plants left. Will they increase in size due to theoir being given all of the light at that point.