I'm finishing up my first grow and had the same questions as you and almost the same size space with two northern lights ...ive got some Afghanis from herbies also that ok doing next ... My setup is a 4 ft wide x 2ft deep x 5ft high custome box I fit in a sliding door closet the same dimensions as yours ...SCROG is the best way to go for max yield . I went back and forth on SCROG and decided not to because I didn't have a good way to let my plants drain (soil) so I had to water in the bath tub removing them from the box which would've been impossible if they were screened in , also scrog from what I've read needs a good two months of veg , I wanted more of a perpetual flow, I topped just above the second node to get for main colas and then kept super ripping them to let the lower branches come up , I love supercropping now its a great method and will probably do this everygrow
... To each is own it really just depends on what you want to do if your able to leave your plants in one spot throughout flowering and don't mind waiting SCROG , if you want to be able to turn your plants or remove them from time to time supercrop, fim ,top ,lst ...
not an expert by any means and this is my first real grow with known strains but my way completely filled my box with 2 plants vegged for 30 days .. Good luck