The beginnings of any science are found by looking at nature, not by pursuing abstractions, or making assumptions about what we can find, based on what we think science must find.
The problem is that observing nature, in the sense of history and evolution, is difficult, in fact, impossible in the case of deep time.
But at least in history, we have the requirement that we must attempt to say what happened at the level of centuries, decades, days.... Please note that evolutionary theory voids that requirement because it claims on the basis of certain abstractions that certain things must have happened, wether we have observed them or not. So much for evolutionary theory then.
In history, at least we can begin to see at close range what is going on. And that can lead to my 'turning point analysis', which simply says that we see clusters of significant events, and this gives us clue to some sort of dynamism.
World system theory began by noticing one aspect of this, the rise of the modern, but only in economic terms. But these two approaches connect just there.
From there others such as Frank have tried to extend that to a five thousand year interval. Again that intersects with the eonic model which makes a similar extension.
The eonic model tries to add the missing piece, the cluster zone in the middle sometimes confused with the Axial. Unfortunately in my experience students of economics can't get over this hump, because the data isn't economically oriented. We have to deal with something much broader. But, be that as it may, the structure nature shows us is a 'world system' showing a general sequence of three clusters.
There it is, if we can grasp what we are seeing.