Its hard for me to compare because they are different strains. The ones in the 4 gallons are clones, and the ones in the 20 Gallons are from seed. The seed plants are all 6ft tall and the clones are about 2.5-3 ft. Big difference, but a few possible causes.
So you are going outdoor and indoor? Sun and T5's? If you have at least a month before harvest, depending upon the size of the plants, and the last time you transplanted, it may be a good idea to put them in a fresh container with fresh dirt.