Point being, why are we all trying to define what "Insurgency" is? Is it to somehow validate the current ideas about COIN?

The whole problem is the propagation of the belief that there is this separate and distinct thing called "insurgency."

It's not useful and it obscures more than it clarifies. COIN is "countering an insurgency." So what? Calling Irregular Warfare "COIN" paints you into a corner where all problems are COIN problems, and thus you readily risk misreading the type of conflict you are fighting in.

To my mind, one of the most telling things (as I have said before) is this is "Small Wars" which is very old language. We might try speaking the old language more and gaining more clarity from it.

And Niel... I fully accept that you are locked into a organisation with it's own language, and in order to make headway you have to speak that language. Good job and good luck. I merely suffer no such constraint.