No offence to Sami Zayn, but had anyone out the loop tuned into Raw last week as he donned the overseer's stripes guest officiating the show's main event, they'd be forgiven for thinking the Underdog from the Underground was a regular ref.
Perhaps Vince McMahon's lack of confidence in his roster's star power is understandable, in this context. One can imagine the boss despairingly watching on as his heel slapped the mat totally indistinguishable from the John Cones and Mike Chiodas of this world, whilst fondly remembering the time his supernaturally veiny biceps bust out the refs top just three years prior - when he was already in his seventies.
Not to keep going on at him, but simply put, Sami wouldn't pass the fictional airport guest referee test. Part of the appeal of a regular superstar donning the stripes is in seeing their usually ludicrous bodies transplanted into a role reserved for 'real' people. These aren't real people, after all: they're superhumans.
Some wrestlers have went above and beyond when it comes to making a spectacle of superintending. They say in football that good refs shouldn't be seen. That absolutely doesn't apply to wrestling's special enforcers.