You could plant the tubers 4 inches down, and whatever sticks up out of the ground can do so. Don't be alarmed if some sprouts shrivel up or fall off. Most likely, the tubers will resprout with a much better start of a plant.

Some growers just nip off the sprouts within a half inch of the tuber, and patently wait for a new sprout.

I do both, depending on how I'm feeling in that nano-second of time, and on how the tuber/sprout are looking.