You should never put snakes together unless you are planning on breeding them. Snakes are solitary animals and prefer to be away from other snakes unless they are looking for a mate. Snakes will eat each other. Snakes only see other snakes as one of two things . A mate, or food. When i first started keeping snakes i started with corn snakes. I bought two and housed them together. They both died. Housing multiple snakes together is also bad because you can have a better chance of disease transfer between the animals. I can't stress this enough you should never ever keep multiple snakes housed together for long periods of time.
Yes you can i have three ball pythons all between 2 and 2 and a 1/2 feet in length they are almost always together when basking and when in various hiding places in there cage which is 4 feet long by 2 feet wide by 3 feet high so they don't need to be that close if they did not want to be.
Its possible but not recomended as the stress from seeing/feeling the other one.
