this topic, like every other, is divided. I really think to some degree you just have to use common sense and observe. I'm sure that just like people, some snakes can roommate and some can't.
Hell, we're human ... we can't possibly know what goes on in their heads, I'm not going to try to figure it out.
If I notice that mine don't seem so happy down the road I'll seperate mine, but for the time being it seems to be benefiting one particularly well.