Lights and yield question

From a fellow grower:

  1. 1000w led Vs 1000w HPS/MH in a 4x4 tent yield and quality (assuming everything goes perfect), which is a better option?

  2. Im having trouble understanding the seeds potential yield… For instance, Amnesia Haze says 600g-650g per plant; and to my understanding you can get about a gram per watt on the light. So one solo plant growing under a 1000w hps light should get full 600-650g? If this is the case why do people grow multiple plants (4-6) under one 1000w lamp.
    if I plant 4 seeds will the yield be quadrupled?
    I hope I explained my question well.

If you grow the entire season it will be that much. But it’s probably being too liberal with the numbers and I have my highest doubt it’s accurate. People grow more than one and shorten it’s growing period so they end up with the same amount in half the time as growing one plant the entire season. People also grow to sell and distribute so more is better.