If a game does not have a little luck or randomness in it to produce a little chaos, then something is wrong. Lots of games scale such things as morale, unit cohesion, suppression and even casualties. Some of the methods used are exercises in bean counting. That is hardly chaotic!
Morale is often taken care of by a random roll of the die. A failure could mean that the unit’s morale status slips by one level or it could mean it simply routs off the board. This is a fine enough method but seems predictable in the sense that the player unnaturally manages his luck with the actual level of morale of the unit. Most generals in real life will only see that a unit is having some sort of difficulty and is, perhaps, ready to crack under pressure. Games like On to Richmond, Fire and Fury and even the fantasy game Age of Might and Steel use a random roll for the actual effect of morale. This is usually done when the unit is in close proximity of the enemy or has suffered losses from enemy action. The results can run the gamut from revenge to rout, all in one roll. There are modifiers that make a rout unlikely (or impossible) for a relatively fresh unit. The effect, though, is that the commander no longer can manage the morale of a unit by simply counting beans.
You can manage suppression in a modern game with the same mechanism. A unit might have to hunker down, advance slowly or even retreat. Two Hour Wargames’ Chain Reaction system does this very thing. Again, it adds a lot of chaos and unpredictability while adding LESS detail. Who said more detail is more realistic anyway?