I think you've really tried to push the description of Combat as War into an entirely ridiculous direction. What does the number of random encounters have to do with Combat as War again? Why would having set encounters mean that it's not Combat as War? Combat as War is really more of an attitude about solving the conflict (violent or otherwise) that encounters (whether random or set) pose and the openness to be able to put any plan that appears effective into place - even if that means upending the expectations of the encounter.
As far as the equally as weird side debate about real-world rules of warfare, it's helpful to note what those rules attempt or attempted to do - and that's control warfare on a particular ideology's terms. Ultimately, when you compare with a realist view of warfare (such as that described by Thucydides) you come to realize that rules of warfare whether based on Chivalry or Geneva Conventions mainly serve to try to turn War into Sport. And to do so on terms favorable to the more powerful actor - the strongest individual warrior, the best equipped warrior, the nation with the biggest army.