I would not keep them together. You might get away with it if you do but there are a few things to take into consideration.
First of all, they don't need massive cages, you can give each an Exo-Terra cage that won't take up too much space. You can build a nice rack or shelf that these cages can stand on. I keep my adults in the 60x45x60 cages and they do very well.
When they are adults, feeding them together can be a huge problem, they will certainly all sit together at the best temperature spot no matter how spacious the cage and not apart. It is not easy moving these snakes and moving them might stress them then they won't eat. If you give them a big enough cage that has more than one heat source then you might as well get separate cages.
They are a bit more nervous snakes, so they might be bothered by a cage mate and then not eat. If stressed they might also strike out at a cage mate.