I strongly maintain the 'Metodo' is the best formation. Used by Italy in 1934 and 1938 World Cups, of which they won both.
Link to image of formation:
http://www.kyle-jackson.co.uk/wp-content/uploads/2010/09/metodo_eng.png
Unorthodox, yes, but revolution is only generated through creativity.
Effectively 2-3-2-3, looks like 2 W's on the pitch.
When attacking the Defensive 3 push up to support the attack, then you have 2 playmakers playing behind 2 wingers and a centre forward.
However, there is fluidity; when defending the 2 wingers drop pack alongside the 2 playmakers to make a midfield 4, and the defensive 3 drop back alongside the 2 foundational centre backs, creating a defence of 5. The central defender of the 5 who was a central midfielder (alongside the 2 wing backs) when attacking fulfils a Libero role.
So, effectively, when attacking you play 2-3-2-3, and when defending players drop back to create a 5-4-1 formation. This fluidity means you can have men piling forward in attack, and you also have a solid defensive basis.
In terms of Southampton, I would play: Boruc - Fonte, Forren - Clyne, Schneiderlin, Shaw - Ramirez, Davis - Rodriguez, Lambert, Lallana