Emergent systems need to have all logic decided at the local level, but have global-level outcomes emerge.

In emergent systems, all decisions are local but they have emergent global consequences.

You can't get a bird's eye view to coordinate, which is necessary for top-down convergence in a large system.

Many problems can't be framed this way, with a successful macro level outcome without a birds eye view, but some subset can.

These are typically grown, budded off of other systems that are working.

But a true bird's eye perspective is an impossibility anyway.

The constraint of "local information only" feels overly restrictive, but it's close to the real constraint anyway.