The absence (or indifference, or incompetence) of government leaves a power-vacuum
That is the intended end.
which will be filled by the savvy.
One would find it optimal that a society reflects cooperation among the savvy.
Humans are basically selfish babies.
Any system that REQUIRES humans to act as intelligent, self-reliant, adults is doomed.
By extending your reasoning, you're either stating that governments are doomed, or that governments don't require humans to act as intelligent, self-reliant adults.
And like ALL organizations (organisms) it becomes self-protecting and self-interested (proto-government).
One type is not "more inclined" than another.
So then how is your allegation that proto-governments will emerge in the advent of anarchy a criticism when juxtaposing centralization and decentralization if "one is no more inclined than the other"?
Although a HOLACRACY takes better care of its own members than a traditional FEUDAL HIERARCHY.
Holocracies are doomed aren't they?
Because humans are basically selfish babies.
If I raise chickens and my neighbor raises pigs, we might agree to trade some number of eggs for some number of strips of bacon.
This is a nearly symbiotic (purely voluntary) relationship (as long as bacon and eggs are not considered necessities).
However, if a third neighbor also raises chickens and undercuts my bacon price, I have to pay more eggs to get my bacon.
The cooperation between neighbor 2 and neighbor 3 comes at "my expense".
No it doesn't. This presumes that you have a claim to a fixed price of goods. What if neighbor three isn't in the picture, and neighbor two solicits more eggs because his pigs aren't reproducing at his desired rate? You're over-producing because your hens are extremely fertile, and your roosters are incredibly virile. The scarcity of your respective products are different and would, therefore, affect the price--or the standard to which you're willing to trade. The boost in price may be inconvenient but that doesn't inform that a boost in price has "come at your expense."
Furthermore, I believe "self-interested" is more apropos (though, unfortunately, the English Language doesn't offer much latitude in making the distinction between the two.) So then the solution becomes simple: conceive and rationalize a moral standard which is fundamentally premised on self-interest. The only moral standard that's consistent with respect to the aforementioned directive is individualism. And by extending the premise of self-interest, we can conceive and rationalize autonomy, sovereignty, and voluntarism. Individualism, for lack of a better term, harmonizes the plethora of self-interests by acknowledging individuals discretion to be self-interested. And since it's a moral standard, it is sustained by those who respect the premise and rational extensions.