This is a good question and one I'm probably not qualified to answer but...

In the military, in initial training, a certain aggressive demeanor is utilised to keep the recruits in a state of unrest at all times. There is nothing calm about it. The idea is to break down the civilian to a point before they can be rebuilt as military personnel. It is not done personally, to hurt or destroy the recruit, it's done to assist the transition and create an effective soldier and is the fastest way to do so.

So, maybe that's one case in which anger and disorder can be fabricated to create something positive?

In certain sports a coach may fashion anger and disorder to motivate also. Boxing, MMA, full-contact sports maybe.

Just a couple of possible situations I guess. I could be wrong, although on the first one I am not.

When not to be calm?

The loss of a loved one will destroy a calm demeanor, as will the production of adrenaline in the body, that's what adrenaline is all about - The fight of flight thing.

Calm on the battlefield can be an advantage with the leadership, just as being the opposite can with the enlisted, hence all the training soldiers go through.

One wants the JTAC to be calm when he's calling in precision air strikes in danger-close situations, they are trained for it, but a soldier in a firefight will not be calm, they will be amped and simply rely on training and muscle memory to perform their job.

So, I think there's cases where it can be an advantage. Clearly there's also cases when it would be of detriment. One must know and act accordingly...But many do not.

This is just my opinion. I'm no expert on the matter.