This 3-4-3 formation feels so natural to Xabi Alonso, I think he is only trying to improvise with the 4-2-3-1 formation and perhaps he is scared of getting bashed by media for playing 5 defenders at a big club like Madrid or Chelsea, but with what I have seen so far, he really should stick to 3-4-3, it suits him so well and he understands it perfectly.