As for Turcopoles, you have a point there, and in the 15th (but especially 16th) century there was a revival of similar types of light cavalry which lacked a lot of heavy equipment – the so called Uhlans, the original (Hungarian style) Hussars, the Jenetes in Spain and so on. These tended to appear in places with sustained warfare between different types of fighters.
The Spanish also developed light troops like rodeleros and so on.
But even these remained a minority, and an adjunct to the main fighting force, whether you are talking about Turcopoles in the 12th Century or light Hussars (as distinct from the heavier armored Polish type) in the 16th. You didn’t have entire (or majority) armies of light troops routinely winning battles until much later, really 17th Century.