I have a feeling Wink rehearsing High Rollers was more about the rotating mini games. In one of the rehearsals I saw, he was otherwise speeding through it until they came upon the game they were using that taping day, at which point they slowed down, and there was increased off-stage chatter back and forth on how it would be presented, etc.
But when it's the day-in-day-out rehearsals for the tech crew and/or the contestants, we see the stand-ins: just to name a few, we know (from the trading circuit and/or this board) that Johnny Gilbert did Headline Chasers, Rich Jeffries did Password Plus, and the contestant coordinator(s) host the Jeopardy! rehearsals.
-Jason