It's never a good idea to house 2 snakes together period if you want healthy snakes. Risk of disease transmission upon arrival, risk of aggression, feeding competition, lack of being able to keep track of who does what, different requirements (humidity, heating), and overall space competition.
They will compete for the best spot in the cage, which may be variable at any time, and that is NEVER a good thing. Even if it looks okay, it probably isn't.