Autos in living soil and pot size

The question is would you run four autos in 10-gallon pots or three autos in 15-gallon pots?

My understanding is that with living soil, you want LARGE pots, beds if possible right, so I'm reluctant to consider 10's...

I am currently running a couple photos in two 25-gallon pots (living soil). Would it be just as good to use those and plant two autos in each one???