Ramsey was player of the season 2013/14. He's 24. Cazorla was close to player of the season 2014/15. He's 30. Ramsey's mix of goals & defensive work isn't available from any other player in the squad. He is the future. Cazorla's control and passing are miles ahead but especially at 30 he's not quick or direct enough to be a winger. The combination just doesn't work, but Ramsey is a much more important player in the long term.