Why do you think the state is the stable equilibrium phase? Please elaborate, I'm not sure that I understand what you're getting at.
Without state organization, large populations must disperse. If they grow too much again, they will again disperse. In an area with growing population density and nowhere to disperse easily, state organization must emerge or be adopted, or the population will die off, possibly causing a ripple through other populations. Who would tend to adopt state structures to defend themselves. Everything tends toward state production and reproduction above the family or smallhold level.