Good communication is more about players doing their jobs as planned, and changing the role if needed/told to do so. Saying back left gone means jack**** if the guy responsible for the zone switches sides for no apparent reason and it gets filled. The american teams are good at passing info around the field and switching a role to a player more able to control wherever an opposition player may have moved to.
But like Pete said, unless the technical abilities of the players involved are honed to a similar, high standard....there aint much point practising that kinda thing. It's amazing how many novice games you can see where some lardass is yelling position calls for the sake of doing it, unable to see where players may actually be, and causing more harm than good. They'd be better off not speaking.. and just gunning and playing off each other as they go...but hey, live n learn.....slowly n expensively.