I went with my escalation definition because it seems to me to make the most sense based on my conception of both insurgency and civil war. And I do think that, as you pointed out, you can have an insurgency going on within a civil war (depending on the territory in question). I honestly don't see most of these things as being as cut and dried as we might prefer. But then again, I also don't see the Indian Wars as being insurgencies, either....