Back to the BP situation... I see no benefit with housing ball pythons together unless it is for a short stint mating.

1. Competition for best perceived spots in the tank.
2. Domination of one snake over the other (AKA, following each other around the tank, snakes curled up together in a pile, etc)
3. Stress from competition and domination can lead to a suppressed or compromised immune system.
4. Stress can lead to illness and most common refusing feed.
5. Pre-mature breeding, leading to possible complications from young mother.
6. Having the possibility of a few eggs hatching, and now having to feed and house hatchlings.
7. Possibility of cannibalism
8. ZERO QUARANTINE, leading to spread of bacteria, disease and parasites (ALL animals should be QT for at least 60 days in a separate room following strict rules)
9. Unless you observe the animals defecating, you will not have a strict idea of which animal defecated and when.
10. If animals are sick, you have no idea who's poo is who's.
11. Your animals are mis sexed, and the males combat
12. BP's are not social animals at all

I could go on if I had time to think about it.

The benefits far out-weigh the risks.

Sand is not advised as a substrate for BP's due to the abrasiveness, limited cleanliness, impaction risk. Better to go with Aspen, coconut fiber, cypress mulch, bark.

It is much easier to buy a tub or reptile enclosure for the second snake appropriate for it's size and the climate control and space limitations are going to be easily achieved.