1, 3, 4, 2
Those numbers are out of sequence. The brain gets confused.
1, 2, 3, 4
Now the numbers are in sequence. Your brain makes sense of the overall meaning -- "we're counting from 1 to 4."
A story is a sequence of events
But not random events. Each event has a particular quality placed at a specific location in time.
If the events are out of order, the brain gets confused and loses focus.
If your email sequences are out of order, your current subscriber gets confused and loses focus.