If you did a search on this topic you would find a lot of info on this, including debates on this issue. Look at it like this- all of the pro ball python breeders in the world spend thousands of dollars on rack systems with individual units for individual snakes. If the snakes got along together when housed together, wouldn't they avoid all of that extra cost and say, keep groups of females together and groups of males, and then just pair them for breeding? Keeping them together is just asking for problems. Why would you want two in the same enclosure anyway?