You have a fundamental misunderstanding of both how a grid in blackout mode appears to a lonely inverter and what means of coordinating inverters that are available to said inverter.

Imagine you're trying to coordinate a choir of ten million singers that are scattered across a radius of a thousand kilometer, that all sing into their individual Ham radio. And you need it to come out in a perfect unison that sounds good for those who tune into the mixed broadcast.

"A problem of coordination" is perhaps correct, but it neglects the difficulties involved