I worked at an establishment some time ago. One shift tended to have higher tips. However, coworkers could trade entire shifts if they wanted. After what I imagine was a LOT of complaining, the tips eventually became evenly distributed. Customers complained when they were, uh…quietly notified of this decision. Nothing changed however apart from customers generally tipping less. Oh and coworkers stopped willingly picking up shifts unless they were on particularly good terms with the person asking.

So yeaaah, not surprised.