9 plants in SOG (3x3 6 or 7 L pots), less time in veg (usually 2 to 4 week max for most hybrid or indica some sativa could use straight 12/12 from seed or 1 week veg), much faster harvest than SCROG, oportunity to observe the phenotype variation from a strain
i personnaly do 8 plants (4x2) for 90x60x180, eventually also check grower like leonweed or daisynabis if you want to see what a good SOG look like
in your case i,ll keep the 5 plants like they are in SOG will work flip into flowering when they are around 25 cm tall no need to top, lst or scrog or what so ever; just need to remove a few lower stem and bud site that are bottom of the canopy and don't get enough light ( 4x4 11L pot is another option for your set up but it would require a slighty longer veg and taller tent 2m 2m20 that's why 9 plants in 6 to 7 l pots is a better option with 180cm)