I've seen some workouts where there has obviously been little to no rehearsal of the moves. The background exercisers are having to wing it. Aaron Lankford's
PowerKicks, for example.
Or, some instructors can't cue their way out of a wet paper bag. I remember one workout (can't remember the instructor) that had consummate background exerciser, Robin. (She was in some Kathy Smith and other videos back in the day.)
In the video, the instructor's cueing was so bad that Robin went the wrong way and bumped into the other befuddled background exercisers more than once. That will make a person who is
not uncoordinated, look uncoordinated.
I am appallingly bad at even the easiest choreography. I took a RAMP class with Gin Miller at a convention. Her cueing was excellent. My brain was not. Thank heavens there was a lot of room between exercisers because I was a danger to myself and others, LOL!