>A successful campaign needs rapid coordinated efforts, which are best delivered by hierarchical models.
This may be an argument for the superiority of militarist states (e.g. Assyria, Prussia), but it's anachronistic for the study at hand, which deals with the type of situation prevailing in e.g. the pre-civilization and pre-organized army Neolithic.
I'm sure Neolithic tribes liked a good quarrel as much as anyone, and the models do scale down. My group of brutes has a charismatic, fairly specialized leader with good tactical skills and huge biceps; he imparts clear, undisputed commands on the battlefield and knows how to plan a nightly raid on your women. Your group of brutes is a bunch of equal individualists, with no real specialization and where each brute does his own thing, resulting in endless diatribes about "why should we defend your cave and let my cave get raided?". Maybe you have an outstanding hunter, but he can't leverage the others as easily and effectively as my uber-leader... until the tribe is so beaten down and numbers are dwindling so much that they cave in to the hierarchical model and let Best Hunter be the boss.
I'm generalizing here, but there's so much we don't know about those times...
The key word in your example is "undisputed". The successful group that you describe must have previously adopted a system of beliefs that elevates some individuals over others. (It's a system of beliefs, and not sheer physical force, as even the strongest individual can be overpowered by a coalition of the disgruntled.) For the purposes of this paper's model, it doesn't matter whether the distinction is based on strength, beauty or purported magical powers.
This may be an argument for the superiority of militarist states (e.g. Assyria, Prussia), but it's anachronistic for the study at hand, which deals with the type of situation prevailing in e.g. the pre-civilization and pre-organized army Neolithic.