No, you don’t have to bribe the oracles with the amount of every tier 1 staker in aggregate to make an attack economically rational. Under a cryptoeconomic rational assumption, you can bribe all the oracles of Chainlink with a broken umbrella and a crayon it would still be the economically correct decision for the colluding tier 2 oracles to refuse to acknowledge any tier 1 wrongdoing when they’re called in to a dispute, and then there will be no punishments for anyone in the entire system*.
