Comment by card_zero

Similarly, a mindless swarm doesn't present much opportunity for tactics, compared to a group with individual self-preservation instincts, and a manipulatable group morale level, or individual fear level mechanisms. On the other hand it's true that realism is not the goal. Reality is no fun, that's why we're playing a game. But it's a sort of distorted echo of reality, I suppose.

I see somebody in another comment complaining that enemies who get frightened rob the player of the fun of battles. So it depends what it's all about.