Ya know, Grow, it really depends on your goal. (I am a poet, but I don't know it, yet my feet show it.)
IF your goal is (because of legal considerations) to be safe - then just use one plant. I don't know where you are, or what the legal limits are, but, back in the day ... the difference in charges (if you got busted) between one plant and four was pretty big. So, back in the day, I would really try to limit the number of plants in my garden so that I'd only do a year in jail instead of ten. I've never been busted (came close) but I truly believe that's because I used (and still do) an abundance of caution.
IF your goal is to produce the most weight as quickly as possible, I would go ahead and plant all four. Situate them more towards the corners and direct side growth to the center. All the other 'rules' I posted above still apply. You can call it a SCROG or a SOG or a hybrid of both - but that will produce the most fruit the quickest. You will get to 75% coverage much faster, so you'll get more crops per year and be more efficient.
Happy growing.
~ Auggie ~