agree, need to think different here, think light and penetrations, even big HID lights dont do much for a plant after 3 feet and only top 1-2 will be top buds, indoors you need to grow small bushes with a even canopy instead of tall plants, train em, top/FIM and/or LST
a SoG is also a option
keep all the Buds even and close to the light, grow many small plants instead of a few big once, Veg 2-4 weeks instead of 6-9, some even go 12/12 from seed
or use a Net over them in a Scrog and grow a few plants and Veg em or longer filling the net, same result with few seeds/plants but longer Veg time