The Axiom surrounds are actually quite different from the Aperion ones in one important respect - there are 4 drivers, not 2. There are the two you can see facing at (roughly) 45 degrees to the sides, but there are also upwards and downwards firing drivers. Also, so far as I know, the Axioms are not switchable in this respect.
That said, the Axioms are VERY forgiving on placement. I just went through this process myself (indeed, I asked a question very much like your own on these forums last week), and there are very few places where they won't work reasonably well.
As I mentioned above, you can put the Axiom surrounds on the wall behind you - but I wouldn't suggest directly behind - spread them out and up if possible, and you should be fine.
