Too many people imagine AIs are somehow "perfectly rational" and therefore will never disagree, they'll just tap into a unified decision making engine and automatically integrate all of their knowledge.

In order to integrate knowledge you need more knowledge. And in order to integrate that you need more still. It's turtles all the way down. If anything, AIs are at a disadvantage to humans, because we at least share a body, an emotional palette, and to some extent a cultural timeline. AIs have nothing to ground the beliefs of the other in.

Theoretically it means that two AI should be able to reach a consensus pretty quickly without needing to share a lot of information.

Unfortunately you need "honest, rational Bayesian agents with common priors" for this to work. Given that humans rarely agree with each other, it's interesting to think about where we fall short of that criteria.

We like to think of logic as 1+1=2. But logic is more like A+B-C*D/E=F. Where any number of those being either completely unknown (we sometimes do not even know we are missing them), or some wide range of potential values.

Most doctors I've spoken to without a personal relationship refuse to comment and instead refer to a specialist.

... Which forces the patient to make his or her own choice, even though they most information they have is a summary from hurried medical professionals.

I understand why they do it, but it's a suboptimal result compared to their weighing the relative merits with their expert knowledge in at least one and offering advice.