Mass movement in PC?

[Outlaw Josey Wales]

Even in peace time on maneuvers, units will stray, move slower than they can or supposed too, a Bn not ready to move when they are supposed too, etc etc. There is always a delay or speed up because there are too many factors and people involved. That gave birth to the expression of moving like an accordion. Don't know when that came about, but, it really sucks.