A question about full backs

I find the main problem with players like Johnson is they just dont go with their runners, they ball-watch. A quick one-two sets the opposition winger's free.

Full back is probably the easiest position to play in football imo and in my experience. Its not tactically demanding compared to other positions you only have to worry about making overlapping runs and to be honest, its the easiest position to defend in if your a decent defender because its next to the by line so, you can hold off attackers easier then any other area on the pitch. That's of course if your up against a world class winger like ronaldo or messi etc, But them type of payers don't count in my opinion they tend to drift into a more central position striker position during the match so they don't really stick to their formation.