Well, conceptually, yes. BUT, how long does it take to fill a given space? 1 plant in a 5 gallon SIP can fill a 5x5 text given enough veg time, say 7-8 weeks. But 3-4 plants can fill it with say a 4-5 week veg which means you can get more cycles in an indoor setup in a year with smaller plants.
That's the theory with SOG (Sea of Green) which is growing I seedling per every say 6 sq" and go 12/12 from seed. No veg. All you get is one main cola but more cycles per year and that maxes out your space.
So, it's about compromises, and whether you grow from seed or clone, what your watering setup is, etc.
But that's why I like having two spaces, one for veg and the other for flower, so that way I can minimize the down time in the flower space.