If the majority wants a certain government, how is the minority going to defeat them with guns? The majority will have more guns.
That's a good and necessary question.
If all it took to construct a building was to stack stones upon each other there would be no science of architecture and no point in writing The Fountainhead.
If all it took to fight a war was to use brute force without rational input there would be no science of warfare or any such thing as a military organization.
If all factors were equal in warfare then a simple majority of combatants would win every time. But in reality all factors are never equal. Thus the purpose of military science is to identify the factors that favor one side or the other and use or negate those factors to one’s advantage.