When I started with my balls I had one 55 gallon tank for one ball. Now I have them in tubs. Are the snakes "happier?" well they eat better.
Pros: you "think" your balls are happier (not true they are not cuddling they are compeating for the best spot in the tank)
They have "room to roam" (also not true as balls don't like to be exposed so all that space is going to waste )
Con: when one snake gets sick who is it?
When you get a regurgitated item who did it and why?
one or the other is getting the prime spots
you have to separate before feeding
It is harder to maintain proper temps and humidity
The list goes on and on for the cons and is very very short for the pro's (that is if you can find one) as balls are not social animals. In the wild they do not seek out company (except to breed) then go their separate ways.
I am giving you the benefit of the doubt that this was an honest question and not trying to stir up people as there are TONS of threads about snakes living together. Some reasons are graphic and tragic.
p.s yes they "can" live together and if you can not for some reason have them live apart then (hopefully) it won't kill them, but honestly why take the chance? We are not trying to bash you but there are some strong feeling on this topic.