You gotta get real bruh, a noob could pull 3 lbs from that easily.
Here';s an old growmau5 video where he does a 1200w HPS vs. 1200w of cxa3070 cobs (last gen) mixed with a bml spydr 600.
1064 grams from the 1200w HPS,
1774 grams from the 1200w of last gen leds. And that's only the top shelf bud, zero popcorn larfy buds. Several of his strains are low yielders too.
Both his LEDs are an average of around 42% efficient after losses. The 6 sammy strips pushing 900w would be 50% efficiency after losses, and
@Takeshy's insane 36 strip 900w build is pushing 55% efficiency after losses.
So it's seriously not rocket science to see how you can pull those yields dude. Stop pretending like it's some crazy unrealistic bullshit. 3 pounds from 900w of strips would be a cakewalk.