War Is Chaos... Mmmm. Yes I can see your point.
It's not my point, it's just what transpires from reports and military mémoirs of this period.
With the smoke and the noise it would have been difficult to get an overall picture of what was going on
Not only because of smoke and noise but moves too : charge, counter-charge, retreat for rally or not, fleeing units, etc.
Armies did break and flee en-masse.
I can't agree with this.In Austerlitz, Allied left wing and center fled but right wing under Bagration retreated in order ; in Montmirail French left wing was overwhelmed and fled but the center and left wing retreated in orderso so it's wrong to say tha an army break and flee en-masse.
where the enemy just leave a regiment at a time is not realistic
I advise you to read how the left Allied wing units was engaged in Austerlitz.