From experience, WSU is dreadful given how narrow the concourse is !
However it seems to me that food and drinks ought to be separated AND prices should be set at even amounts - pies and pints etc. not requiring change.
In other words, staff handing out required items instantly in the food kiosks and some staff dedicated to pouring pints in the drinks kiosks and not to order !
Narrow the concourse is? christ have you been to QPR, Man Utd,Liverpool or Everton? I could carry on