For those who conclude that violence is the only option left in a conflict, it's great that a course is offered on how to do that wisely.   

But while the Portland attacks show how quickly a conflict can turn to violence, it does not mean all conflicts have to end in violence.
There are many ways to diffuse a conflict so that it doesn't rise to the level of violence.    I would say this is almost always your best first choice of action.   Once a gun is pulled the bar for response is moved to deadly consequences.

Personally I've never been in a live situation where deadly force was in play. (I'm 63)   That doesn't mean it couldn't happen, but lets be realistic about how far we want to go in preparation for such an event.   

It also raises the question if training for such a conflict, might bias a persons choice of escalating to a weapon when it may not be needed.    I would suggest pro-active stance of recognizing conflict and a broad range of approaches to diffuse such conflict.