It's a matter of insight and understanding, not the amount of knowledge. Most people not only find history to be a most boring topic, but they pathologically think they are going to find the "quick fix" magical answer to one of the most complex matters ever to be conceived by us human beings. For an example, let us take these aforementioned horse-archers and try to chart their weaknesses. Let us get the scope of their continued use within general militaria, from the age of the Cimmerians and early Scythians, to the age of the late Tatars.

Their function in the battle-field was more or less the same throughout the ages, yet they must have continuously surpassed their own short-comings throughtout the generations through different tactical adaptations and different strategical paradigms. It easily gets esoteric, which is a far cry from "heavy cavalry beats light horse and spears beats horse and blades beats spears". These are all over-simplifications, and if one cannot understand the basics of the real life tactical flexibility of a military element, there is no point for me to ramble on about it either.