Yep, 5-2-3 is the shape. Walker as the right CB to allow his pace to cover the flank behind a marauding right wing back, and to also bring the ball forward to supplement numbers in midfield.
Of the two CM's, we tend to play one deeper playmaker type - the role that Henderson has excelled at for Liverpool. This is our key position (and one that's overlooked in the press), as it allows two styles. Firstly, against most teams who will sit deep against us, dropping Henderson back allows him more time and space to pick out a pass. It's not dissimilar to Pirlo's role in his best years at Juve.
And secondly, against more gung-ho opposition, he will be close to the defenders when we win possession, which allows them to feed him a simple pass and then he can hit longer direct passes looking for the pace of Sterling, Rashford or Alli.
Our second CM tends to be the 'shuttler' type - getting up and down the pitch, linking the midfield with the attack, picking up defensive duties in the middle and filling in space in the attack.
The main differences in our system seem to come in how the front three are lined up. Southgate has recently leaned towards a triangle, with a central Sterling playing behind two strikers - Kane and one other. But we also work well with the classic wider front three of a Central Forward who can hold the ball up (Kane), a direct attacking Left forward (Rashford or Alli) and a right forward who's job it is to find the space (Sterling or Welbeck).
Having said that, we are set up to be structurally sound with the back 7 players, allowing the front three to roam and be more fluid. So it'll probably chop and change on a game-by-game basis.