Well, it would only take one floor sized piece of wood (4x2) to turn one 4x2x2 cage into two 4x2x1 cages. For the minimal amount of work it would add to your building project, your boas would get substantially better care and be much "happier". Like Trevor said, snakes generally don't live together in the wild and often become stressed out if they need to compete for hiding spaces in captivity. They are secretive animals who live solitary lives.
So, the answer is... no. Of course you could go against this advice like 1/2 of the people will but your snakes will be better off if you just give them each their own enclosure.