Based off of your other descriptions of the animals, I doubt a small husbandry change would help these pythons, and the staff at that particular store are a huge problem.. BUT
your description of the tank is against petco policy. Ask them to review their planograms. Ball pythons at petco are required to be on either aspen or eco earth, have at least 1 hide (I know, it would be better if there weren't 3 together, but this is not against petco policy), and a large water dish.
If you'd like, I can find the contact information for their disctrict manager so that you can express your concerns. I cannot stress enough however, to always remain calm when 'telling people their business'. If you come across as trying to help and not telling them how to do their job (even if you are fully in the right), nothing you say will matter.