It's possible and some people do, I've done it. I've went back to single tanks myself. 1 bacteria infection in section 1 can take out sections 2 and 3 in days.
20g platy, , 2 x 10g shrimp, 3 x 20g shrimp, 7.5g shrimp and 1 great dane/mastiff puppy.
Sump Pimp #2
My Tanks and my shrimps