Thanks for the explanation. Good point about staking, assuming if the validator is chosen before, then they are certain to get the chance to order the transactions in their favour.

The article, as I understood, the caller predicts the outcome of the 'random' function first, and then calls if the result is favourable. It seems like yours is more efficient, as it relies on using revert() to undo all state changes, if the outcome was unfavourable, so no need to predict anything!