its a while since I played the scenarios where this was a major feature.
But if I recall, you don't order it as such. It just means that if units with that trait (mostly Indians) take a structure they will try to burn it down. There is a limit to what can be damaged - cities over a certain size can be destroyed etc.
I maybe making this up, but I also think that units with the raiding trait are more likely to plunder a region if there is a battle there.
So in the French and Indian wars scenario, over time both sides will lose settlements etc, especially south of the Lakes, as their various Indian factions capture and lose regions.
AJE The Hero, The Traitor and The Barbarian
PoN Manufacturing Italy; A clear bright sun
RoP The Mightiest Empires Fall
WIA Burning down the Houses; Wars in America; The Tea Wars