They were using sports celebrities as the draw to the table, not expert poker players.
Cheating at poker also looks less threatening than playing against an expert, counterintuitively. Someone who cheats can pull out some big wins on some bets that look statistically bad. The target can see this and think the other party is playing poorly (betting on non-obvious hands) but simply getting lucky.
Contrast this with a shrewd expert poker player who will be easier to spot.
They want the target to think the celebrity sports figure is just getting lucky on bad bets, not that they're an expert poker shark who's going to take all of their money.
That's a big "just".
They were using sports celebrities as the draw to the table, not expert poker players.
Cheating at poker also looks less threatening than playing against an expert, counterintuitively. Someone who cheats can pull out some big wins on some bets that look statistically bad. The target can see this and think the other party is playing poorly (betting on non-obvious hands) but simply getting lucky.
Contrast this with a shrewd expert poker player who will be easier to spot.
They want the target to think the celebrity sports figure is just getting lucky on bad bets, not that they're an expert poker shark who's going to take all of their money.
EDIT: Here's a 2 year old YouTube video from before all of this confirming this https://youtu.be/G-TKR5ca5jI?t=1790 (Skip to 29:50)
Having the cheating poker players look bad is a key part of the scam. It tricks the other players into coming back and betting big.