Ball pythons don't really fight -not like mammals at least, you would not see them biting and hissing at each other - they would more likely be "snuggling" or curled on top of each other. The "loser" would be forced away from the hide and temperature it wanted and would be unable to self regulate since the dominate snake would keep the choicest spots. This can lead to meal refusals, stress also makes them more susceptible to disease / RI infections. Not to mention if they are opposite gender - resulting in unwanted eggs. Snakes don't form emotional attachments to things, they won't care that they are separated. They are alone in nature except to breed, their biology does not change when in captivity.

You will have healthier snakes if they each get their own proper space