jhg said it very accurately "they can determine risk very accurately". Excellent statement!!!
They ARE different critters in the dark, they ARE much more aggressive when travelling together, and during breeding season a big male is highly unpredictable.
I believe coyotes are not all the same. Certain areas where I live contain `yotes that are much larger than the average, and live more as a pack animal. They are not all frail, sneaky, mouse eaters.
One, close range encounter with the yellow eyes of a forty-plus pound male, defending his territory, and you will know there is nothing to fear...as long as you can make him aware the risk is too high.