You have described a slide defence and plenty of teams use it and it makes it more difficult for opposition teams to create an overlap because the defending players work together to move laterally across the field, sliding in unison. This is used to combat and attacking team that uses a lot of width in theri attack, The defenders move side to side, maintaining their spacing to cover the entire width of the field, making it difficult to break the line. It is used to cutting off the attaacking options and forcing them towards the sideline and also helps to deal with the 3 on 2 situation with the cover defenders and sideline used to deal with the overlap. The big disadvantge is that it gives the oppositon time and space = speed and momentum. You trade risk for ground.
We are primarily using an up and in defence similar to Penrith and Melbourne; it is a more aggressive, pressure-based strategy. In this system the aim is to shut down the attack by getting up in their face. Indoing so you don't give the play makers time to act or players like Ponga or Best the room to move. The down side, as you have seen in both trials, is that when you misread the play or fail to engage decisively (Lobb) here can be a large gap created for an attacking player to exploit. Fitness and cover is an essentail component.
We should have the ability to switch as required, but the game plan agaisnt Ponga and Best, with aweaker centre pairing shoudl be up and in to limit opportunities in attack.
I triust this clarifies how to best stop the fullback from swweong effectively.
