I don't think that mitigates the trust issue. [EDIT: Nevermind, see next paragraph.] Even if dumb oracles are ubiquitous, you never really know if a given oracle is really one of the dumb ones or just a wolf in sheep's clothing. You can pick a set of supposedly dumb oracles at random and hope for the best, but regardless, you're still trusting that if Bob tries to bribe them, at least one of them will stand firm.

Ok I just realized that does mitigate it. "1 of 15 is honest" is a mitigation compared to "8 of 15 is honest," for example. It mitigates by "reducing" the number of trusted third parties, which is wonderful. But it only reduces it to a number that remains greater than 1. At the end of the day, trusting that "1 of N is honest" is still trusting the integrity of a federation.